In an older post on his blog Mohamed Said demonstrates how you can leverage virtual columns to speed up queries on data stored as JSON.

Laravel 5.3 is shipped with built-in support for updating and querying JSON type database fields, the support currently fully covers MySQL 5.7 JSON type fields updates and lookups, ... Let's see how we may create a generated column to store users favorite color for later indexing.

https://themsaid.com/laravel-mysql-json-colum-fast-lookup-20160709