You can exclude the cameras by camera name or by camera_id using the NOT operator as described here in the Hook query.

camera name

If an account has 64 cameras and you want to exclude 3 indoor cameras named Lobby, Storage Room, and Kitchen, then the Hook's query would be:

NOT Lobby NOT "Storage Room" NOT Kitchen

Alternatively, you can enumerate the cameras that you do want to trigger Hook callbacks, but when the camera count is high, it's better and easier to exclude the smaller count of excluded cameras using the NOT operator.

camera_id

You can also exclude a camera by using its camera_id with the NOT operator like this, which excludes two camera_id values:

NOT gd:00vx12273wf6fvd:14A78B651961:14A78B651961.0 NOT gd:00vx12273wf6fvd:14A78B651961:14A78B651961.1

p.s. Note that the camera names are case-sensitive and that multi-word camera names must be in double quotes currently.

p.p.s. - the use of camera_id is supported only in Hooks (not the general search engine yet)