When you say certified do you mean as in certified to teach in a public school?
In my state to hire a noncertified person (via an emergency certificate) in preference to an existing properly certified individual would be inconsistent with Dept of Ed rules--but in a way nobody enforce said rules in favor of the bypassed individual as I see it!
Most places I think age 40+ puts you in protected age category--so if somebody in authority said you were too old and you can prove it and they hired somebody much younger you just might have a case!
But in general the employer can do as they darn please--they can require 5 years of XXX experience , turn down an a applicant with 4.9 years of specific experience and hire somebody with 0.0 years of required specific experience