SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    1503, 285, 1826, 1646, 1580, 1906, 1611, 
    1166, 67, 1252, 1930, 1561
  )

Query time 0.00088

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 12,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (1503,285,1826,1646,1580,1906,1611,1166,67,1252,1930,1561)"
    }
  }
}