SELECT 
  product_review_id 
FROM 
  cscart_product_reviews 
  LEFT JOIN cscart_users ON cscart_product_reviews.reply_user_id = cscart_users.user_id 
  LEFT JOIN cscart_companies ON cscart_users.company_id = cscart_companies.company_id 
  LEFT JOIN cscart_country_descriptions ON cscart_product_reviews.country_code = cscart_country_descriptions.code 
  AND cscart_country_descriptions.lang_code = 'en' 
WHERE 
  1 
  AND cscart_product_reviews.product_id IN (391030) 
  AND cscart_product_reviews.status = 'A' 
GROUP BY 
  cscart_product_reviews.product_review_id

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.02437124,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_reviews",
          "access_type": "ref",
          "possible_keys": ["idx_product_id"],
          "key": "idx_product_id",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["const"],
          "loops": 1,
          "rows": 9,
          "cost": 0.01550208,
          "filtered": 100,
          "attached_condition": "cscart_product_reviews.product_id <=> 391030 and cscart_product_reviews.`status` = 'A'"
        }
      },
      {
        "table": {
          "table_name": "cscart_users",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["user_id"],
          "ref": ["u985510652_ecartify.cscart_product_reviews.reply_user_id"],
          "loops": 9,
          "rows": 1,
          "cost": 0.00886916,
          "filtered": 100
        }
      }
    ]
  }
}