Think about this. If just a little bit of John Coffeys gift includes a longer lifespan, imagine how old John Coffey was himself. He says “Im tired of never having a buddy to be with”, because hes always outlived all of his friends. “Whered you get all those scars?” - I think its a reference to slavery. Its 1934 when the events take place, so JCs a minimum of 90 years old when he meets Paul. Could be even older.