SELECT 
  product_id 
FROM 
  cscart_mb_ali_products 
WHERE 
  product_id IN (
    20061, 20062, 20063, 20064, 20065, 20066, 
    20067, 20068, 20069, 20070, 20071, 
    20072, 20073, 20074, 20075, 20076
  )

Query time 0.00015

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 (20061,20062,20063,20064,20065,20066,20067,20068,20069,20070,20071,20072,20073,20074,20075,20076)",
      "using_index": true
    }
  }
}