SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '937c9cde78eda2f7400b5c97aaa96c4ba599645bb7c6f3f53ce14b395d31a35b' 
  AND token = '2Vkziyzs0qNLscWF8YNZV+8PkGUBAZnNVt/Zwr+NTos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}