Yes, it's a McDonald's. From Scouting New York:
McDonalds purchased the property with the intention of tearing it down and replacing it with a standard McDonald’s restaurant. Thank God for the citizens of the New Hyde Park, who worked to secure landmark status for the building in 1987.
McDonald’s had no choice but to restore the property and work within the parameters of the landmarks commission, which ultimately resulted in their most beautiful restaurant in America (if you know of a better example, please let me know).