SN74AHC1G09-Q1: SN74AHC1G09QDBVRQ1

For the actual power consumption, see [FAQ] How do I Calculate Power Consumption or Current Consumption for my CMOS Logic Device?

For the maximum, you have to ensure that the junction temperature does not exceed the T_J limit. So with the DCK package at the maximum ambient temperature, this would be (150 °C − 125 °C) / 293.4 °C/W = 85 mW. (When using the rated output current of 8 mA, the worst-case dissipation is 4.4 mW.)