SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '87a29db989cba6d869e98240a7e95d308a8a9d686a2fdf2fb477e2729e757a05' 
  AND token = '5ddZ9rAjTFIT4rOXiQCJNoX7CndnZdEDtehpfMSOJZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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