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 (
    296, 297, 293, 294, 308, 302, 306, 309, 
    298, 299, 300, 301, 295, 329, 326, 325, 
    324, 322, 323
  ) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00039

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": 36.53845978,
          "attached_condition": "cscart_product_review_prepared_data.storefront_id = 0 and cscart_product_review_prepared_data.product_id in (296,297,293,294,308,302,306,309,298,299,300,301,295,329,326,325,324,322,323)"
        }
      }
    ]
  }
}