Python Create unix timestamp five minutes in the future

I have to create an "Expires" value 5 minutes in the future, but I have to supply it in UNIX Timestamp format. I have this so far, but it seems like a hack.

def expires():
    '''return a UNIX style timestamp representing 5 minutes from now'''
    epoch = datetime.datetime(1970, 1, 1)
    seconds_in_a_day = 60 * 60 * 24
    five_minutes = datetime.timedelta(seconds=5*60)
    five_minutes_from_now = datetime.datetime.now() + five_minutes
    since_epoch = five_minutes_from_now - epoch
    return since_epoch.days * seconds_in_a_day + since_epoch.seconds

Is there a module or function that does the timestamp conversion for me?

Copyright License：
Author:「Daniel Rhoden」,Reproduced under the CC 4.0 BY-SA copyright license with link to original source & disclaimer.
Link to：https://stackoverflow.com/questions/2775864/python-create-unix-timestamp-five-minutes-in-the-future