Not as such, because it's a parallel connection, not a serial one - the normal method is to use a 'crowbar' circuit, which shorts the supply out (and blows the fuse) in case of over voltage.
It depends on the amplitude of the voltage and the duration. Sure, if the incoming voltage is large enough, they can fry. But most of the time, MOVs can take a hit and be fine. They are better suited for transient protection rather than lighting if used by themselves.
I have not seen MOVs used as a crow-bar. In the traditional sense of the word, this is not so. You would use thyristor such as an SCR (along with the supporting cast of passives) for over-voltage protection.
I think that it's better for me to specify: I need it little (max 1cm x 1cm x 0.5cm) and for low voltages/currents (5V - 2A must pass, 7V - 2A must not pass). What's best with this requisites?
I think that it's better for me to specify: I need it little (max 1cm x 1cm x 0.5cm) and for low voltages/currents (5V - 2A must pass, 7V - 2A must not pass). What's best with this requisites?
I was going to suggest an MOV, but your specs are too tight for that. It would help if you could provide a schematic or better specify your application.
As already posted use an overvoltage protection circuit, basically a comparator and a thyristor to cause the fuse to blow by shorting the supply voltage.