Catalyzes the liberation of alpha-xylose from the non-reducing terminal glucose of xyloglucan oligosaccharides. Hydrolysis of terminal, non-reducing alpha-D-xylose residues with release of alpha-D-xylose. Optimum pH is 3.0-4.0. Optimum temperature is 55 degrees Celsius. Belongs to the glycosyl hydrolase 31 family.