In case you were going to compare two times
DATEDIFF[
^] will help you , to collect times that have ocurred just in the same minute as now try this :
where DATEDIFF(MINUTE, lastsenddate, GETDATE())=0 and
DATEDIFF(SECOND, lastsenddate, GETDATE())<60
This will give you lastsenddates whose minutes are the same as now.
If you want other alternations execute this query and use its functions in your where clause :
select GETDATE(), DATEPART(HOUR, GETDATE()),DATEPART(MINUTE, GETDATE())
Hope it helps.