"Wasted" a key

[NewDweller]

I was in the dungeon with the ice elemental. I got the key from it, but then
used it at the snake pyramid. It was some sort of absorbed/destroyed.

This leads to the situation, leaving me without matching key. Is there a way out
or do I have to replay everything??

[Dr.Disaster]

What do you mean by "used at"?

All locks inside the pyramid accept only tomb keys. All other keys are rejected, not absorbed/destroyed.

[NewDweller]

It was the outer pyramid door and yes, the key was destroyed

[Dr.Disaster]

There is no lock at the outside of the pyramid. What exactly did you do?

[NewDweller]

Actually the key has been found.

As I didn't know the correct lock, I left-klicked with the key at the door. The
key was rebounced and put elsewhere on the ground. On second visit I found
it laying there.
I would have expected to find it in the inventory.

[Dematto]

Sounds like you threw the key.