How would I find a specific Jira item

In the old version, there was a field on the top right hand of the screen where one enters a key of a Jira item and the Jira item get displayed. This was very useful. It was taken away in the new version.

Question: So how do I find a specific Jira item by key in the new version? It looks like one can search for every possible thing except for a key! or may be we are having a hard time finding it. We prefer the old UI.

Thank you for your help!