If you would like to restrict playback of your track, you can choose to disable app playback through your track's Permissions tab. Disabling app playback prevents supported third-party integrations from streaming your track via the SoundCloud API. This setting does not affect playback on SoundCloud itself or through official SoundCloud embeds.
 

You can disable or enable app playback through the track’s edit page in the ‘Permissions’ tab. Access this edit page at any time through the pencil icon under it's waveform.