I am assuming that you are changing planes at Doha.Given that it is not an enormous airport,interchange times of 45 minutes seems reasonable.
Have a look at this page from the Official Website of Doha Airport.
http://www.dohaairport.com/services.html?links r07
If you scroll down to Arrival and Departure Procedures,you will read that
"As a result of cooperation between different authorities at the airport (security, passports and customs) the procedures and time have been reduced to ten to fifteen minutes"
which of course may be a little optimistic,BUT it is certainly less even than 45 minute.
I haven't trawled through the whole site so there may be more,but the above is reassuring?
Of course this assumes that incoming flights to Doha (both to and from the Maldives) are not in themselves late,that is something we have no control over.
Personally,I would want a flight direct to the Maldives,which would cut out any worry about changing flights;but I assume this would push up the holiday cost?