How to generate 5 MHz clock with 50% duty cycle?
A clock oscillator module requires no more than power connections with a bypass capacitor to produce a square wave output at approximately 50% duty cycle (for example, 45-55% guaranteed). You just need to pick one that is suitable for your desired frequency, supply voltage, output type and accuracy/stability. There may be an enable input that needs to be tied to an appropriate logic level.
If that is insufficiently close to 50% duty cycle, you can procure an oscillator that operates at double your desired frequency (10MHz in this case) and divide the output with a flip-flop, such as 74HC74.
For example, the ECS-5032MV-100 which is a 10MHz oscillator which operates from 1.6 to 3.6V Vdd, plus a 74ALVC74.