SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    1720, 1719, 1722, 1713, 1718, 1717, 1867, 
    1721, 1685, 1207, 1210, 1203
  )

Query time 0.00085

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 (1720,1719,1722,1713,1718,1717,1867,1721,1685,1207,1210,1203)"
    }
  }
}