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 (
    1840, 1841, 1842, 1843, 1844, 1845, 1846, 
    1847, 1848, 1849, 1855, 2915
  ) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.0126454,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_review_prepared_data",
          "access_type": "range",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "7",
          "used_key_parts": ["product_id", "storefront_id"],
          "loops": 1,
          "rows": 12,
          "cost": 0.0126454,
          "filtered": 100,
          "attached_condition": "cscart_product_review_prepared_data.storefront_id = 0 and cscart_product_review_prepared_data.product_id in (1840,1841,1842,1843,1844,1845,1846,1847,1848,1849,1855,2915)"
        }
      }
    ]
  }
}