Can I use relays with 10A125V~ for my 220V~ applications, safely?
The part is obsolete now according to Mouser.  The simple answer is no, you cannot use a 120 volt part at 220 volts.  The higher voltage can breakdown the lower voltage rated parts.  It really has nothing to do with the "power" rating as there will be very little power actually dissipated in the relay.  The current handling of the contacts is one issue and that seemingly didn't change but the voltage rating change is basically saying that this part cannot work at 220volts.