I open the thread to explain this in detail, considering the complication they have had to find this. Any questions in this regard can be discussed here.

As for the 2 lockpicks, I don't think it is necessary to specify it because they are in visible boxes so they are easy to find.

Meanwhile, the normal 5 keys may represent more difficulty. So this is the location, corresponding to the latest update of the mod:

-In this area of ​​the cave with ruins of buildings. One key is held by the Aphest "Polda".

-In that same area, to the left of the fire there is a secret passage in the wall, but the tree has to be cut down. Following that passage, upstairs, there is a cave with a chest containing a key.

-In this same area there is a descending passage where there is another cave, in that place there is another descending passage cutting another tree. This leads to another cavern with enemies, to the right is another passage that leads to another cavern where there is a closed door. Nearby is the buried key to open it.

-Returning to the upper path in the beach cavern, in the area where there is a group of Beasters, there is a key buried in a visible place near the group.

-The last key is on the penultimate map where there is a group of Beasters and buildings, it is this map where the door that leads to the battle against the blacksmith is. The key is under an urn.