A long time later, when we're closed? (5,5)
I believe the answer is:
after hours
'when we're closed?' is the definition.
(a place might not open after hours)
'a long time later' is the wordplay.
I cannot quite see how this works, but
'a' is within the answer.
'time' could be 'hour' (unit of time) and 'hour' is present in the answer.
This explanation may well be incorrect...
(Other definitions for after hours that I've seen before include "Late" , "when we're not open" .)