To write a config-value, we need two database queries at the moment. One, to load the old value and one, to write it. This is not necessary. ConfigStore.objects.filter(key=key).update(value=value) should work:

```python
updated =  ConfigStore.objects.filter(key=key).update(value=value)  # .update() returns the number of updated rows.
if not updated:
    ConfigStore.objects.create(key=key, value=value)
```
Even nicer would be a method ConfigStore.objects.create_or_update() bat I couldn't find somethink like that.