Do multi-use keys get discarded when finished with?

As with many resident evil games, you sometimes needs to collect certain keys to open certain doors, and resident evil 7 has plenty of these around.

Some keys are clearly single use, and get left in the lock in which you use them. However, there are a number of keys that can be used on multiple doors. For example, the Scorpion Key.

I am concerned that I might end up carrying these around needlessly and using up valuable inventory space, so...

Do these multi-use keys get discarded when you use them on all the doors they apply to? Or do you get a warning saying the key is no longer needed? (like previous games are known to do)

Solution 1:

The keys are not automatically discarded when there are no longer locked doors that they open, and you don't get any messages letting you know that you don't need to carry them around anymore.

You also can't discard the keys manually, even if you've used them on every door they lock. That probably makes inventory management on the "Open the equipment chest only 3 times" challenge even more painful.