Most of my literature puts A time at 1-1.5 hours for 6 weeks to 3 months,
While too long A time gives 45min naps, SOOO too does too short & I actually think 1 hours is a wee bit on the short time for a baby approaching 3mo. I know both my boys were pushing the 1.5 hours at that stage
What I would suggest doing it keeping the hour, but then having a 15min, cuddle & story time & then putting him down for his naps & see how that goes
BTW, my ds#1 used to only do 45min in 2 am naps then a 3 hour mid day & then a 45min around that age & that was after 1.5 hours A time, If he is only doing 45min all day long then the A time sounds to me like it is too short, esp if he is waking up happy from the 2nd one & you can't extend it... normally you can extend a nap more easily if they are overtired.