Could I still be considered looking when I'm in my 50s, 60s, 70s and beyond?

I just turned 40 and people still tell me I'm beautiful. I actually didn't think I'd still get as many compliments at my age. Anyway, I know 40 is still quite young. This sounds vain, but I'm really scared of losing my "beauty". Is it still possible to be a looker later on in life? I sometimes obsess about this.