Can i search for scoped labels by their key?

In the search bar I can enter ~label and it will happily find all issues labeled with said label.

Searching for a scoped label with ~key::value works accordingly.

But how can I search for all labels of the same key?
I assumed it would be possible to use ~key , but that doesn’t work.
I did not find any clue on this in the documentation.

Any hint will be appreciated

kind regards Astrid