That’s really good! I like his expression and “personality”, but, one thing I noticed is that the mouth (and the chin underneath) seems a bit wide. I think this is one thing that might make him look a bit older.
The shadow under the front of the cheeks probably also adds a bit of age, since this slightly resembles that “creasing thing” that tends to happen around that area with age – I’m having a hard time explaining this properly but maybe if you make this transition smoother, either by letting the cheek bones sink in a bit or push the mouth part (upper/lower lip, chin) forward a bit, that might reduce his age a bit too.
Anyway this is just comments in terms of his apparent age, the model itself is great and they’re not “bad” parts at all. But, I think they’re symbols of an older age than you’re going for perhaps.