If it's really lower back 'pain', rather than discomfort/tenseness, I would take a rest and do some light stretching, if the pain doesn't get less then seek professional help.
If it's just tense/soar/tight/whatever you want to call it, there are a few things I do to eleviate pressure from my lowerback:
1. seated goodmornings: Focus on relaxing your lowerback on the bottom-part, this is not so much about building strength but rather to stretch your entire back out by allowing it to round a little. Obviously shouldn't use too much weight (I usually use an emptybar or maximum 40-50kg).
2. Hanging upside down with the aid of 'gravity boots': great way to decompress your spine, especially when you 'wind up' by twisting your body.
Just hanging upside-down usually already makes a ton of difference.
3. Foamroll and/or 2 lacroseballs in a sock ('peanut'). to release soft tissue:
Real simple, roll around a little, promoting bloodflow, or finding 'blockades' and just lay on that specific spot for a moment until it 'pops'. Basic idea is that by stimulating the soarspots or imperfect spots of the muscle, you allow it to stretch out and evenout, releasing tension. (But I'm confident most of you already use/know about the use of foamrolls/lacrose balls).
4. Walk it off.
Works for me sometimes.
It might also be worthwhile to check on the tightness of your glutes/hamstrings and upperback, as usually the lowerback is affected by those, and is not necessarily lowerback specific. As with everything, the pain should either be relieved or become less over time, or seek professional help.