If the water was fresh (not sewage backup, nor saltwater), and it was not standing in the water for long, it is possible little or no damage has been done. However, before using, you might clean the outside, particularly cooling fins and condenser coils, and interior evaporator coils, with diluted bleach and detergent from a spray bottle, then rinsing thoroughly with a hose.
The compressor and its motor are sealed, and should be fine. However, some components might have been damaged:
- If the water was high enough to cover the control boards, likely at the top, they might be ruined.
- The fan bearings might have rusted.
Surprisingly, most electronic components can be soaked in clean water, and then dried thoroughly, and still work! I've washed and dried USB flash drives, accidentally, with no ill effect. The "catch" is that the device must not have power applied while any moisture is left. If the remote control had batteries and was immersed, even cleaning might not get it working due to electrolytic corrosion.
After drying the AC as much as feasible (do not apply excessive heat!), and waiting a few weeks with a fan blowing over it, plug it into a GFCI receptacle. If there is dangerous electrical leakage, i.e., shock hazard, the GFCI will pop off, with no harm done. If it runs when plugged into the GFCI, and it cools, and blows air without making excessive noise, then it's likely OK.