·You should be able to look whatever you want, even old.
·I`ve been in lots of situations where the first thing the hiring manager asks is the candidate age and drops the CV as soon it finds out is older than 35.
It's just in many countries it's illegal to ask that question, and from my experience working for a couple of Australian and (1) US companies, no one gives a shit about your age, as in the number. Your manager/workmates don't care, HR doesn't have a criterion for it, it's illegal and that's my answer to the question.
Again they may care if you are really old.
I know back in my home country in Asia it's legal to have an age criterion.