It should. I had the same issue with my mk4 gti. The key would only go in half way. Luckly i had a way to open from the inside. Anyways 2 years into having the car i decided to wd40 the lock an poof it worked.
I would try that. So have you not been in the trunk at all? Could treasures await you!?!?!? Go through the rear seat lol