My opinion… You may technically get too “old” to kick your leg up like you can now (and heck, too “old” could be 75!), but I see no age boundary to singing and acting. Act 'till you drop!
That being said, many people will say that if you can see yourself doing something other than MT, then pursue that. There are numerous opportunities to perform in MT in local theatres while working your day job.
Day job - 8:30-4:30
Theatre rehearsal - 7-10.