Как-то так:
SELECT id, time1, time2, time3, LEAST(t.time1, t.time2, t.time3)AS min FROM `toster_666564` AS t ORDER BY min
Результат:
UPD. Можно и так, чтобы min не выводить
SELECT id, time1, time2, time3 FROM `toster_666564` AS t ORDER BY LEAST(t.time1, t.time2, t.time3)