Yes — on a DSLR this is normal. In Live View, the camera is already using the sensor continuously to feed the rear LCD, which means the mirror is up and the shutter is open. When you press the shutter button, the camera typically has to close the shutter first, reset the sensor, then open the shutter again to make the actual exposure, and finally close it at the end.

Through the optical viewfinder, the sequence is simpler: press the button, mirror flips up, shutter opens for the exposure, then closes. That usually feels faster.

So even in manual focus, Live View can have more shutter lag because of the extra mechanical and sensor-reset steps required before the exposure starts. Autofocus can add even more delay in Live View, since DSLRs often use slower contrast-detect AF there instead of the faster phase-detect AF used with the viewfinder.

On some cameras, settings such as exposure delay mode can also affect timing.