artodeto's free port

SET @expired_timestamp = DATE_FORMAT(NOW() - INTERVAL 23 MINUTE, '%Y-%m-%d %H:%i:%s');
SET @valid_datetime = DATE_FORMAT((NOW() - INTERVAL 42 DAY), '%Y-%m-%d');

SELECT 
  `column_with_datetime`, 
  @expired_timestamp AS 'expired_timestamp', 
  @valid_datetime as 'valid_datetime'
FROM 
  `my_table` 
  WHERE 
    `column_with_datetime` >= @valid_datetime;