Non professional user perspective comment: There are no guarantees but in many cases it has a reasonable chance of being OK if cleaned well externally. Significant salt water INSIDE a system will destroy it in time. If you can afford it, professional cleaning will give peace of mind. If you wish to gamble then there is a good chance of winning if you clean externally s best you can.
I'd be as worried about the lens as about the camera. I'd do lens as well as camera cleaning as below with lens at full zoom.
Use a clean absorbent cloth (such as a facecloth or toweling), make very damp but not dripping and clean all over the exterior several times.
If you are not averse to sticking things in your mouth (some people are very much so, some care little), before you start clean a finger in fresh water, wet it in fresh water, wipe finger tip over camera and taste you fingertip. Salt will be tastable prior to any cleaning. After cleaning it should be not able to be tasted. (Licking you camera achieves this more directly :-) ).
Remove lens and see if there is any hint of water intrusion. If there is ANY sign that salt water has got in you probably want to ask about professional cleaning.
If you are confident of your ability to touch thing in the mirror box you could consider cleaning all surfaces that you are sure are not going to be damaged with a dampened bud. It would be very unwise to touch any mirror or optical screen surfaces with anything. (Lens surfaces are OK).