Cool, I've done thousands in a month. Do thousands every year.
But if your bike doesn't have two brakes as you have stated, it doesn't matter how many KMs you ride, because you are not getting that experience to inform you.
I’ll back him up - I do thousands of kilometres a month and log component changes when they happen!
My rear brake pads last about 5000km before they need a change, my front brake pads last about 3500km.
It would appear by observation of the consumables that the front brakes do the most work. This is in-line with my expectations from the experience riding the bike and established knowledge about how weight transfer works in vehicle braking - there is a reason cars always have bigger discs on the front and some cheap hatches still have drums on the rear.
But if your bike doesn't have two brakes as you have stated, it doesn't matter how many KMs you ride, because you are not getting that experience to inform you.