SET @start_date = CAST('2018-02-20 12:30:01'AS DATETIME);
SET @end_date = CAST('2018-02-20 14:29:59'AS DATETIME);
SELECT * FROM table
WHERE
(date_from >@start_date AND date_from <@end_date)
OR
(date_to >@start_date AND date_from <@end_date)
OR
(date_to >@start_date AND date_to <@end_date)