This is the 183rd most frequent Swedish word.
borta
Gone; away.
The word 'borta' is used here to indicate that the keys are not present or have been misplaced.
Nycklarna är borta.
The keys are gone.
Here, 'borta' is describing the distance or separation of the location from the city.
De bodde ganska långt borta från staden.
They lived quite far away from the city.
In this sentence, 'borta' is combined with 'i hörnet' to indicate a specific distant location within the context of the room.