Nothing thwarts a craft project in progress like realizing your glue is hard and dried. Cryanoacrylate glues, once hardened, cannot be re-softened. Your glue may be thickened and extra-sticky after you soften in hot water, but it will likely serve its purpose until you can get to the store and buy more.
Fill a saucepan with water.
Heat the water until it simmers.
Turn off the heat and drop the sealed bottle of glue into the hot water.
Leave the glue in the water until the water cools.
Open the cap on the glue bottle and see if the glue is soft enough to use. If not, repeat the process.