To reach your stated goals, you’ll need to boost your FTP by roughly 30-40 watts (according to Bike Calculator), which isn’t easy for someone like yourself who’s already at a high level. A lot of folks in your position start piling on volume.
If your genetic potential is high, you might be able to get there without that much volume, but I think if you can stretch your workouts to 60 minutes, you’ll see some improvement.
45 min is very little and is more along the lines of Sprint Interval Training. SIT uses 30-second sprints to fatigue your body into overall fitness gains. It’s something you can try and will probably net you some gains, but it’s not really a year-round type of program.