SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_destination_products_amount 
WHERE 
  product_id IN (
    5439, 4354, 5214, 5006, 5449, 5440, 5049, 
    5362, 4998, 5363, 4999, 5242, 5241, 
    5243, 5244, 5245, 18039, 5138, 5441, 
    5000, 4393, 4394, 4395, 5034
  ) 
  AND destination_id = 115 
  AND storefront_id = 0

Query time 0.00065

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": 75,
      "index_condition": "cscart_warehouses_destination_products_amount.destination_id = 115 and cscart_warehouses_destination_products_amount.storefront_id = 0 and cscart_warehouses_destination_products_amount.product_id in (5439,4354,5214,5006,5449,5440,5049,5362,4998,5363,4999,5242,5241,5243,5244,5245,18039,5138,5441,5000,4393,4394,4395,5034)"
    }
  }
}