As another possibility, maybe he glimpsed Rey in a Force vision, and knew right away this was someone important.
If that’s the case, maybe Kylo learned about her (or even met her) when he was still training under Luke as Ben Solo.
Was Kylo Ren merely interested in Rey because of what his officers told him ahead of time and because he eventually learned she could tap into the Force?
Or is it possible he knew about Rey before the main events of this movie?