You can use gradient PCR from 56-64 C, generally we're selecting annealing time on the basis of Tm ; if your primer Tm is 63.5, so Tm-5 C, you can select annealing temperature.
As your FP having Tm= 63.5 and RP Tm= 64.5 , therefore, ideally annealing at 55 is the best option. You can set your gradient cycle either 2 or 5 degree interval and consider your annealing temperature range in between 50-63 degree.