That's 100% a scam.
Phishers try to guess what companies you might do business with - Booking.com, Facebook, PayPal etc - and send you emails with urgency and deadlines to get you to click the link. When they guess wrong and you get an email from a bank you don't use or a company you don't deal with it seems immediately fake but this is just as fake they just guessed correctly.
If you check the link it probably goes to something like "booking-reservation-now.com" or something else fake that is designed to sound Booking.com affiliated but is not..
If you do deal with Booking,com just go to their site and check to see if there is a message for you and I bet there's not.
It has nothing to do with Booking just scummy people being scummy. Be safe you there everyone.
=Tod