SELECT 
  product_id 
FROM 
  cscart_mb_ali_products 
WHERE 
  product_id IN (
    20461, 20462, 20463, 20464, 20465, 20466, 
    20467, 20468, 20469, 20470, 20471, 
    20472, 20473, 20474, 20475, 20476
  )

Query time 0.00013

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 (20461,20462,20463,20464,20465,20466,20467,20468,20469,20470,20471,20472,20473,20474,20475,20476)",
      "using_index": true
    }
  }
}