How would colleges know that an essay is 40 words longer than the limit?
If you have to copy/paste it into a textbox to submit the essay, it will be cut off at the word limit. You won’t be able to paste the rest.
If you’re submitting it as a document electronically, it’s not hard to open it and check the word count, or to copy it into another document to do the same.
If you’re submitting a physical copy, maybe they have interns whose job it is to sit there and count words. 
Why would you risk it???
40 words shouldn’t be hard to cut. PM me if you’d like help.
I am surprised that you think college admissions can’t count. 40 words can be trimmed.