SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_sum_products_amount 
WHERE 
  1 
  AND product_id IN (
    50982, 133, 45, 143, 50983, 51416, 51043, 
    51421, 51471, 51413, 51057, 51472, 
    51547, 51470, 51500, 51412
  )

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "17.06"
    },
    "table": {
      "table_name": "cscart_warehouses_sum_products_amount",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 29,
      "rows_produced_per_join": 29,
      "filtered": "100.00",
      "index_condition": "(`test_uchur_k`.`cscart_warehouses_sum_products_amount`.`product_id` in (50982,133,45,143,50983,51416,51043,51421,51471,51413,51057,51472,51547,51470,51500,51412))",
      "cost_info": {
        "read_cost": "14.16",
        "eval_cost": "2.90",
        "prefix_cost": "17.06",
        "data_read_per_join": "464"
      },
      "used_columns": [
        "product_id",
        "amount"
      ]
    }
  }
}