Drupal 7 - How do I parse JSON data from a website and import them as Nodes and have them update hourly?
I think you have a problem with the "context", and title query. I've tried this configuration and worked for me.

The context is the first query and in this case just selects all the nodes, the second one takes the value of the key "last" ant put it on the node title.

Then you can play with other querys, to create the nodes, but at least this one works.