SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_sum_products_amount 
WHERE 
  1 
  AND product_id IN (
    558893, 558889, 559332, 563215, 558919, 
    558821
  )

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_warehouses_sum_products_amount",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 6,
      "filtered": 100,
      "attached_condition": "cscart_warehouses_sum_products_amount.product_id in (558893,558889,559332,563215,558919,558821)"
    }
  }
}