indeed -you are on good track two multiplexers for X and Y are the typical solution for  sensor arrays. However, one should not forget "dangling" sensors connected to your measurement setup with only one terminal. This can be crucial with regards to capacitance sensors; while for current sensors still may need to be considered.

Another issue is multiplexer itself - channels are of limited resistance - (non 0! and in solid state parts it's not unusual to see values ~200Ohm) and may have some leakage current. Another option is to make your own multiplexer from discrete reed relays - this minimizes resistances and current leakage.