Am I too late? Aspiring for a toned body

I, ~40M, always aspired to have a great physique, abs with muscles and all. Never got time in my life so far to look after myself because of other commitments. Slowly I am realizing that I should have tried fulfilling my aspirations and desires too. I am 5 feet 10 inches tall and I weigh 78 Kgs today. Is it loo late for me to try for a toned body? If not, do I need to take any precautions as compared to younger folks? P.S. I am a healthy person with no past history of health problems. I am a regular walker with a minimum of 60 minutes a day of brisk walk.