External Power Supply on RF 315/433 MHz Transmitter-receiver Module

One last question, I'm using the cheap moisture sensor YL-69. It will be plugged on the arduino board of the receiver, it will send data every hour to a database. However, I know that this sensor get damage easily, so I want to power it only when I read the data (when it will send the data every hour). Do you have an easy way to do that ? I need to use a digital pin right ?