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 (
    301, 300, 299, 298, 297, 296, 295, 294, 
    293, 292, 291
  ) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_review_prepared_data",
          "access_type": "ALL",
          "possible_keys": ["PRIMARY"],
          "rows": 3,
          "filtered": 100,
          "attached_condition": "cscart_product_review_prepared_data.storefront_id = 0 and cscart_product_review_prepared_data.product_id in (301,300,299,298,297,296,295,294,293,292,291)"
        }
      }
    ]
  }
}