No. You will probably excel in a graduate program because you have the experience of living a few years and you will most certainly take your studies seriously. My mother went for her graduate degree at 38... She was, at the time a secretary at the firm and ended up senior partner before all was said and done. Go for it!
A 45 year old man is not too old to pursue a master's degree. As the saying goes, education has no boundaries and thus, no one is ever old to do something. More so, at that age, is the best time to pursue the masters when he has little responsibilities to meet.