An outbound REST API was built to access a remote system via MID server.
When the API is called either by script or manually, it always fails with the specified 60 seconds of timeout.
The system log may show that was an error in processing the response body, and this is because after the timeout happens there is no response body.
Any supported release
The MID server is down, and because of this condition the REST probes times out.
This may happen if your instance was upgraded, but the MID servers are still in an older release.
Always check that the HTTP Call is set to use a MID server that is up and running.