Hacking into a jammed glove box could either be a quick fix or a dramatic part of your day. There could be multiple solutions to apply to this specific problem.
Try the key for the glove box again, even if it is for the third or fourth time. Wiggle it, then jiggle it again, or slide the key slightly out and in again. Sometimes keys are simply not cut perfectly or are too worn to easily undo the mechanism. While we are on the topic of trying the key, check to make sure that you have the right key. If you are using a valet key, it will not unlock the glove box.
Hit the glove box really hard a couple of times. Maybe it is just jammed and needs some force to get unstuck.
Spray WD-40 or a similar compound into the latch mechanism. Perhaps it’s just stuck and needs a lubricant. Then, repeat Step 1--and, if necessary, Step 2.
Try sliding a credit card along the slot of the lock if you can access it. This is the oldest trick in the book, but many door locks can be “picked” with a credit card just by sliding it to the underside of the lock. However, most glove boxes are secured and latched in such a way that this probably is not viable.
Try picking the lock with a safety pick and tumbler wrench. This may take some practice and know-how. Try turning the lock both clockwise and counterclockwise. Keep pressure on the lock and insert the paper clip, jiggling it around.
It may be possible to remove the entire glove box. Look for exposed hinges or screws. While it is not very likely that any of the hardware securing the glove box will be exposed, if it is, removal may be one of the most viable and least costly solutions. Just remember how to reinstall it, and keep all the small parts in one place.
If all else fails, head for the nearest locksmith or the auto dealer, where an employee might have a way to get in without charging you money. If lack of time is a factor, then a locksmith may be your best bet, since you'll be certain the right tools are readily available.