The description of the scrying spell states:
You can see and hear a particular creature you choose that is on the same plane of existence as you.
Instead of targeting a creature, you can choose a location you have seen before as the target of this spell. When you do, the sensor appears at that location and doesn’t move.
The spell does not explicitly state that the location chosen must be on the same plane of existence, seemingly implying that that restriction holds only for targeting creatures.
Can scrying target a location on another plane?