SELECT 
  cscart_product_review_prepared_data.product_id AS product_id, 
  cscart_product_review_prepared_data.average_rating AS average_rating, 
  cscart_product_review_prepared_data.reviews_count AS reviews_count 
FROM 
  cscart_product_review_prepared_data 
WHERE 
  cscart_product_review_prepared_data.product_id IN (
    303, 304, 305, 310, 311, 312, 313, 314, 
    315, 316, 317, 318, 319, 320, 321, 291
  ) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_review_prepared_data",
          "access_type": "ALL",
          "possible_keys": ["PRIMARY"],
          "rows": 52,
          "filtered": 30.76922989,
          "attached_condition": "cscart_product_review_prepared_data.storefront_id = 0 and cscart_product_review_prepared_data.product_id in (303,304,305,310,311,312,313,314,315,316,317,318,319,320,321,291)"
        }
      }
    ]
  }
}