in pix/asa:
sh isa sa [detail]
sh cry ipsec sa [detail]
in ios:
show cry isa sa [detail]
show cry ipsec sa [detail]
here's an example from asa:
asa# sh isa sa detail | inclu time
Auth : preshared Lifetime: 86400
Lifetime Remaining: 86342
asa# sh cry ipsec sa detail | inclu lifetime
sa timing: remaining key lifetime (sec): 7129
sa timing: remaining key lifetime (sec): 7129
