OK - no computer expert here - but most keys on a keyboard will pop/snap off the board. You may have a bit of dried sticky stuff under that particular key. If it was me, I'd try popping off that key and clean underneath.
Keep in mind I know nothing of the type of keyboard you have, so take my "advice" with a bit of salt.
Now having obtained a precious human body, I do not have the luxury of remaining on a distracted path. ~ Tibetan Book of the Dead
There are ways of remapping keys but I can't think of them right now. If you're using windows, the on-screen keyboard might help you figure out which key is stuck. I think on windows its in all programs -> accessories -> accessibility -> keyboard. I could be wrong, but it can't hurt to look for it. Good luck