The experience of the interview itself, may well help you later during an interview for a job you really do want. And, you never know what might eventuate at the interview. You may not get that job in the first five seconds, but, you surely can lose it! Clothes in a current style. Hair cut, and dyed if needed (but, carefully, and, no comb-overs or 50's page-boys!) A firm handshake. Look them in the eye and SMILE. Don't brag about your grandchildren, or mention how many years it's been since you graduated from high school. Emphasize what you've been doing the last 10 or 20 years, no need to go any further back. Omit the year you graduated (unless you have a recent degree).

Summary:
Go to every interview you are offered, even if the commute is impossible, the job isn't what you really want, or the pay is too low. Work on making a good first impression. Don't drop tips that emphasize your age.