SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_destination_products_amount 
WHERE 
  product_id IN (
    2686, 2568, 15042, 14456, 2188, 13664, 
    12195, 14044, 15057, 12955, 2645, 2646, 
    2333, 2331, 2330, 2792, 2793, 11131, 
    2794, 11132, 2798, 2795, 2797, 11890
  ) 
  AND destination_id = 12 
  AND storefront_id = 0

Query time 0.00059

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_warehouses_destination_products_amount",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "idx_storefront_id"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "destination_id", "storefront_id"],
      "rows": 24,
      "filtered": 100,
      "index_condition": "cscart_warehouses_destination_products_amount.destination_id = 12 and cscart_warehouses_destination_products_amount.storefront_id = 0 and cscart_warehouses_destination_products_amount.product_id in (2686,2568,15042,14456,2188,13664,12195,14044,15057,12955,2645,2646,2333,2331,2330,2792,2793,11131,2794,11132,2798,2795,2797,11890)"
    }
  }
}

Result

product_id amount
2188 0
2330 28
2331 0
2333 20
2568 24
2645 1
2646 1
2686 24
2792 46
2793 46
2794 0
2795 0
2797 0
2798 0
11131 46
11132 0
11890 1
12195 124
12955 10
13664 4
14044 270
14456 5