You can use the stats-job(id) command from the client. The server will return the id again, the tube it came from, its state, priority, age, ttr, and other information also described in the protocol document I linked earlier. If your client is non-blocking (and handling multiple jobs), you may also receive a "DEADLINE_SOON" from the server which indicates the job is within 1 second of its TTR (which would also indicate you need to touch the job).
In practice, you may find it easier not to ask about the TTR and instead just send a "touch" command every time your worker has the opportunity to do so *and* if the job is making progress.
Scott