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 (
    8608, 8609, 8610, 8619, 8620, 8623, 8624, 
    8631, 8632, 8635, 8638, 8639, 8658, 
    8659, 8661, 8667
  ) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_review_prepared_data",
      "access_type": "ALL",
      "possible_keys": ["PRIMARY"],
      "rows": 5,
      "filtered": 100,
      "attached_condition": "cscart_product_review_prepared_data.storefront_id = 0 and cscart_product_review_prepared_data.product_id in (8608,8609,8610,8619,8620,8623,8624,8631,8632,8635,8638,8639,8658,8659,8661,8667)"
    }
  }
}