Up to three days, depending on the surface. According to this study published in The New England Journal of Medicine:
The new coronavirus is viable up to 72 hours after being placed on stainless steel and plastic. It was viable up to four hours after being placed on copper, and up to 24 hours after being put on cardboard. In aerosols, it remained viable for three hours.
Please take all prescribed precautions when it comes to surfaces. Clean your work station before and after use with disinfecting wipes, wash your hands often with soap and water, avoid touching your face, etc. Also, be mindful of other surfaces you may be in contact with, such as door knobs, taps, etc.