Hi i fly to Granada a few time a year and it takes me one hour to get to Calahonda So to i would say one and a half hours depending on traffic in malaga.

If you book car make sure it is available at the airport or else you will have a delay to collect it from Granada
By the way Granada is nice to visit
Road to malaga is a dual carrage but narrow and not an easy drive if you are not used to driving in spain

Haven't done it myself but the distance from Granada Airport to Puerto Banus is 110 miles so I guess it could take a couple of hours to drive it.