SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_destination_products_amount 
WHERE 
  product_id IN (
    50998, 50999, 51000, 51001, 51002, 51003, 
    80, 51398, 51399
  ) 
  AND destination_id = 116 
  AND storefront_id = 1

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "6.31"
    },
    "table": {
      "table_name": "cscart_warehouses_destination_products_amount",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "idx_storefront_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "destination_id",
        "storefront_id"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 9,
      "rows_produced_per_join": 9,
      "filtered": "100.00",
      "index_condition": "((`test_uchur_k`.`cscart_warehouses_destination_products_amount`.`storefront_id` = 1) and (`test_uchur_k`.`cscart_warehouses_destination_products_amount`.`destination_id` = 116) and (`test_uchur_k`.`cscart_warehouses_destination_products_amount`.`product_id` in (50998,50999,51000,51001,51002,51003,80,51398,51399)))",
      "cost_info": {
        "read_cost": "5.41",
        "eval_cost": "0.90",
        "prefix_cost": "6.31",
        "data_read_per_join": "144"
      },
      "used_columns": [
        "destination_id",
        "storefront_id",
        "product_id",
        "amount"
      ]
    }
  }
}