SELECT 
  product_id 
FROM 
  cscart_mb_ali_products 
WHERE 
  product_id IN (
    8373, 8374, 8375, 8376, 8377, 8379, 8387, 
    8388, 8389, 8391, 8392, 8394, 8396, 
    8399, 8403, 8404
  )

Query time 0.00017

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 (8373,8374,8375,8376,8377,8379,8387,8388,8389,8391,8392,8394,8396,8399,8403,8404)",
      "using_index": true
    }
  }
}