I don't think Karma means what you think it means.
Karma: (in Hinduism and Buddhism) the sum of a person's actions in this and previous states of existence, viewed as deciding their fate in future reincarnations.
As evidenced by your simplistic answer, "Karma" doesn't mean "You reap what you sow." It means if you are a bad person, you might be reincarnated as a rat or a cockroach.
You're obviously not trying to teach a course on comparative religion here, but you sure are mixing your metaphors into a smoothie without much sauce.
It means, as we pray it, that we are placing ourselves under His Kingdom's dominion, that His will be done (to the extent of a Christian's ability) in us, and in our lives as it is done in Heaven. The answer is both present and future. Yes, God's kingdom is coming here one day in the future, but making Him Lord of Lords and King of kings in our hearts brings His kingdom here in what small area of control we might have hereon earth, beginning with ourselves, our relationships, our families, and our communities. It could be stated "May Your Heavenly will be done in my life," as well as pointing off into the future hope we have in Heaven being brought down to earth. Nothing wrong with asking God to start the work in your life, and bring a little heaven into your existence today.