SELECT 
  company_descriptions.*, 
  companies.*, 
  cscart_multi_decvendor_plan_descriptions.plan, 
  cscart_multi_decseo_names.name as seo_name, 
  cscart_multi_decseo_names.path as seo_path, 
  AVG(
    cscart_multi_decdiscussion_rating.rating_value
  ) AS average_rating, 
  CONCAT(
    companies.company_id, 
    '_', 
    IF (
      cscart_multi_decdiscussion_rating.thread_id, 
      cscart_multi_decdiscussion_rating.thread_id, 
      '0'
    )
  ) AS company_thread_ids 
FROM 
  cscart_multi_deccompanies AS companies 
  LEFT JOIN cscart_multi_deccompany_descriptions AS company_descriptions ON company_descriptions.company_id = companies.company_id 
  AND company_descriptions.lang_code = 'ru' 
  LEFT JOIN cscart_multi_decvendor_plan_descriptions ON companies.plan_id = cscart_multi_decvendor_plan_descriptions.plan_id 
  AND cscart_multi_decvendor_plan_descriptions.lang_code = 'ru' 
  LEFT JOIN cscart_multi_decseo_names ON cscart_multi_decseo_names.object_id = 1 
  AND cscart_multi_decseo_names.type = 'm' 
  AND cscart_multi_decseo_names.dispatch = '' 
  AND cscart_multi_decseo_names.lang_code = 'en' 
  LEFT JOIN cscart_multi_decdiscussion ON cscart_multi_decdiscussion.object_id = companies.company_id 
  AND cscart_multi_decdiscussion.object_type = 'M' 
  LEFT JOIN cscart_multi_decdiscussion_posts ON cscart_multi_decdiscussion_posts.thread_id = cscart_multi_decdiscussion.thread_id 
  AND cscart_multi_decdiscussion_posts.status = 'A' 
  LEFT JOIN cscart_multi_decdiscussion_rating ON cscart_multi_decdiscussion.thread_id = cscart_multi_decdiscussion_rating.thread_id 
  AND cscart_multi_decdiscussion_rating.post_id = cscart_multi_decdiscussion_posts.post_id 
WHERE 
  companies.company_id = 1

Query time 0.00068

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "15.80"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "companies",
          "access_type": "const",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "company_id"
          ],
          "key_length": "4",
          "ref": [
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.20",
            "prefix_cost": "0.00",
            "data_read_per_join": "6K"
          },
          "used_columns": [
            "company_id",
            "status",
            "company",
            "lang_code",
            "address",
            "city",
            "state",
            "country",
            "zipcode",
            "email",
            "phone",
            "url",
            "storefront",
            "secure_storefront",
            "entry_page",
            "redirect_customer",
            "countries_list",
            "timestamp",
            "shippings",
            "logos",
            "request_user_id",
            "request_account_name",
            "request_account_data",
            "tax_number",
            "registered_from_storefront_id",
            "plan_id",
            "pre_moderation",
            "pre_moderation_edit",
            "pre_moderation_edit_vendors",
            "suspend_date",
            "grace_period_start",
            "last_time_suspended",
            "last_debt_notification_time",
            "hotel_name",
            "facilities"
          ]
        }
      },
      {
        "table": {
          "table_name": "company_descriptions",
          "access_type": "const",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "company_id",
            "lang_code"
          ],
          "key_length": "10",
          "ref": [
            "const",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.20",
            "prefix_cost": "0.00",
            "data_read_per_join": "1K"
          },
          "used_columns": [
            "company_id",
            "lang_code",
            "company_description",
            "i18n_company",
            "i18n_address",
            "i18n_city",
            "terms"
          ]
        }
      },
      {
        "table": {
          "table_name": "cscart_multi_decvendor_plan_descriptions",
          "access_type": "const",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "plan_id",
            "lang_code"
          ],
          "key_length": "10",
          "ref": [
            "const",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.20",
            "prefix_cost": "0.00",
            "data_read_per_join": "792"
          },
          "used_columns": [
            "plan_id",
            "lang_code",
            "plan"
          ]
        }
      },
      {
        "table": {
          "table_name": "cscart_multi_decseo_names",
          "access_type": "ref",
          "possible_keys": [
            "PRIMARY",
            "dispatch"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "object_id",
            "type",
            "dispatch",
            "lang_code"
          ],
          "key_length": "206",
          "ref": [
            "const",
            "const",
            "const",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "1.00",
            "eval_cost": "0.20",
            "prefix_cost": "1.20",
            "data_read_per_join": "1K"
          },
          "used_columns": [
            "name",
            "object_id",
            "type",
            "dispatch",
            "path",
            "lang_code"
          ]
        }
      },
      {
        "table": {
          "table_name": "cscart_multi_decdiscussion",
          "access_type": "const",
          "possible_keys": [
            "object_id"
          ],
          "key": "object_id",
          "used_key_parts": [
            "object_id",
            "object_type"
          ],
          "key_length": "6",
          "ref": [
            "const",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "1.00",
            "eval_cost": "0.20",
            "prefix_cost": "2.40",
            "data_read_per_join": "24"
          },
          "used_columns": [
            "thread_id",
            "object_id",
            "object_type"
          ]
        }
      },
      {
        "table": {
          "table_name": "cscart_multi_decdiscussion_posts",
          "access_type": "ref",
          "possible_keys": [
            "thread_id",
            "thread_id_2"
          ],
          "key": "thread_id",
          "used_key_parts": [
            "thread_id"
          ],
          "key_length": "3",
          "ref": [
            "vishalecarter_multi_dec.cscart_multi_decdiscussion.thread_id"
          ],
          "rows_examined_per_scan": 6,
          "rows_produced_per_join": 6,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "5.00",
            "eval_cost": "1.20",
            "prefix_cost": "8.60",
            "data_read_per_join": "2K"
          },
          "used_columns": [
            "post_id",
            "thread_id",
            "status"
          ],
          "attached_condition": "<if>(is_not_null_compl(cscart_multi_decdiscussion_posts), (`vishalecarter_multi_dec`.`cscart_multi_decdiscussion_posts`.`status` = 'A'), true)"
        }
      },
      {
        "table": {
          "table_name": "cscart_multi_decdiscussion_rating",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY",
            "thread_id"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "post_id"
          ],
          "key_length": "3",
          "ref": [
            "vishalecarter_multi_dec.cscart_multi_decdiscussion_posts.post_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 6,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "6.00",
            "eval_cost": "1.20",
            "prefix_cost": "15.80",
            "data_read_per_join": "96"
          },
          "used_columns": [
            "rating_value",
            "post_id",
            "thread_id"
          ],
          "attached_condition": "<if>(is_not_null_compl(cscart_multi_decdiscussion_rating), (`vishalecarter_multi_dec`.`cscart_multi_decdiscussion_rating`.`thread_id` = `vishalecarter_multi_dec`.`cscart_multi_decdiscussion`.`thread_id`), true)"
        }
      }
    ]
  }
}

Result

company_id lang_code company_description i18n_company i18n_address i18n_city terms status company address city state country zipcode email phone url storefront secure_storefront entry_page redirect_customer countries_list timestamp shippings logos request_user_id request_account_name request_account_data tax_number registered_from_storefront_id plan_id pre_moderation pre_moderation_edit pre_moderation_edit_vendors suspend_date grace_period_start last_time_suspended last_debt_notification_time hotel_name facilities plan seo_name seo_path average_rating company_thread_ids
1 en Компания, которая делает лучшее на свете ПО для электронной коммерции CS-Cart Boston street Boston <p>Пожалуйста, внимательно прочтите Условия соглашения ("Условия", "Соглашение", "Условия соглашения") перед бронированием объектов, принадлежащих Арендодателю на сайте&nbsp;<a href="http://www.mywebsite.com/">http://www.mywebsite.com/</a>&nbsp;и в нашем Мобильном приложении ("Платформа"), используемым нашей Компанией ("мы", "наш" или "нам").<br></p><p>Подтверждая бронирование, вы соглашаетесь с условиями, описанными в данном Соглашении. Если вы не согласны с любой частью данного Соглашения, мы не в праве оказать вам Услуги.</p><p><b>Бронирования</b></p><p>Если вы хотите совершить бронирование любого объекта на нашей Платформе ("Бронирование"), мы имеем право запросить информацию, необходимую для Бронирования, включая, помимо прочего, ваши...</p><p><strong>Контент</strong></p><p>Наша Платформа позволяет вам публиковать, хранить, делиться и оставлять ссылки на использовать прочие способы для предоставления информации в виде текста, изображений, видео или в любой другой форме ("Контент"). Вы несете ответственность за...<br></p><p><strong>Изменения</strong><br><span></span></p><p>Мы сохраняем за собой право, по своему собственному усмотрению, вносить изменения или заменять данное Соглашение в любое время. Если изменения значительные, мы постараемся предоставить предупреждение об изменениях в Соглашении как минимум за 30 дней до начала действия новых Условий. Мы сохраняем за собой право на свое усмотрения определять, в каких случаях изменения являются значительными.</p><p><span></span><strong>Свяжитесь с нами</strong></p><p>Если у вас остались вопросы, касающиеся данного Соглашения, пожалуйста, свяжитесь с нами.</p> A CS-Cart Boston street Boston MA US 02125 cs-cart@example.com +16175556985 http://example.com none Y 1269610461 1,6 0 3 N N N 0 0 0 0 Голд cs-cart 1_0