Finishing Undergrad in 2 Years - Impact on Master's Admissions?

In principle, if your GPA is high and your GRE (or equivalent) scores are strong, the academic part of your application will not be affected by the short time to degree. If your interest is in a professional degree, then there should be no negative consequences. However, if you are seeking a degree where research is important, then you have to manage your time very carefully to get the kind of valuable research experience that is generally needed for admission. In addition, extended research experience will lead to a strong personal reference letter for your faculty mentors. These are also essential for admission.

If you provide more detail, it might be easier to provide advice.