Absolutely not. You won't get the kind of roles that 20 year olds are needed to get, but you can still make a fine living as an actor.
You need the right training, the right connections, and the right mindset. Of these, the mindset is the hardest to acquire.
When i wanted to explore my options, i asked a friend of mine who is am independent film maker. He gave me advice and i followed it. Decided in the end that acting wasn't for me. But i was on the right track if I'd had.
First off, if you're not already in an area that gets a lot of action in the industry, you have to move. New York, L.A., Atlanta. That's pretty much it. I'm in Atlanta. Then you have to find someone in the industry to point you in the right direction. Then you have to put in the work. Listen to people that know what they're talking about and do what they say. If you can't do that then you won't make it as an actor even if you were in your twenties.
There's a lot of little things you need to understand about the industry. You can only learn them from others already in it. But at the same time you have to be smart and know who to listen to. With the right mindset it's easy. With the wrong mindset it looks impossible. Plenty of sad sacks out there who love to spread their misery. Never let someone inflict cynicism on you. Agents and casting directors can smell it on you.
It's a common fallacy that success doesn't mean you are right our know what you are doing. That is not true in the industry. The most successful person you know should be the first person you tap for advice. You should be replacing that person regularly with someone more successful. Sounds callous, but it's how it works. Climb the ladder, it's the only way to get to the top.