Yes,
Like others have said, also get your self a can of multipurpose lubricant, WD40 is ok , but
there are others now that actually better lubricant--example here in Ausy one is called RP7
from selleys, and better if it has the long nylon spray extension.
Sqray this down from top or at the lock mechanism , while trying your key at gently at the same time.
Dont worry re spraying over glass etc, can be cleaned off after.