SELECT 
  product_id 
FROM 
  cscart_mb_ali_products 
WHERE 
  product_id IN (
    21165, 21166, 21167, 21168, 21169, 21170, 
    21171, 21172, 21173, 21174, 21175, 
    21176, 21177, 21178, 21179, 21180
  )

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_mb_ali_products",
      "access_type": "range",
      "possible_keys": ["product_id"],
      "key": "product_id",
      "key_length": "4",
      "used_key_parts": ["product_id"],
      "rows": 16,
      "filtered": 100,
      "attached_condition": "cscart_mb_ali_products.product_id in (21165,21166,21167,21168,21169,21170,21171,21172,21173,21174,21175,21176,21177,21178,21179,21180)",
      "using_index": true
    }
  }
}