This quest could be quite annoying as all timed quests are, but there is an easy way to complete it.
1. Get yourself a camel. It's easy to do by finishing this quest: Your Best Friend in the Desert. You can also use a horse or even run on foot using speed powers ups, but camel will save you some seconds.
2. Bert is located inside the Hystria Ruins. The entrances to the Hystria Ruins are spawned randomly in the desert. All possible locations are available here: https://bdocodex.com/th/npc/31090/.
3. I've added two screenshots to the Screenshots tab. One of them shows the locations of the entrances. Circled entrance is one of the closest and spawns at 6pm-7pm by in-game time. Second screenshot shows the map of the Hystria Ruins (original is taken from this Reddit thread: https://www.reddit.com/r/blackdesertonline/comments/cemifa/new_scuffed_hystria_map/). If you'll use the circled entrance you'll land on the spot marked with big red arrow. Then just follow the red line on the map to get to Bert. I was able to do it with 2min left on the timer.

I made a video for this quest here https://www.youtube.com/watch?v=N-9EiCpqxL4

Pour différencier le temple Aakman des Ruines d'Hystria, il faut faire les 2 quêtes ici : https://bdocodex.com/th/quest/5746/1/
Le temple aura une simple aura noire, les ruines aurons l'aura noire avec un halo lumineux tout autour.

Mais je n'ai toujours pas eu la chance malgré les astuces, de trouver ces fichues ruines !

Edit : j'ai enfin trouvé comme par hasard juste après avoir réalisé ces 2 quêtes, le bon portail. Vous pouvez, une fois arrivé dans les Ruines prendre la fuite, ce qui vous téléporte directement sur Bert