Some examples of how to query a json data type field:
SELECT * FROM users
WHERE JSON_EXTRACT(meta_data, "$.first_name") = 'bob';
SELECT * FROM users
WHERE JSON_EXTRACT(meta_data, "$.age") IS NOT NULL;
SELECT * FROM users
WHERE JSON_EXTRACT(meta_data, "$.accepted_policy") = true;
With mysql 5.7.9 +
You can also just do this (shortcut for JSON_EXTRACT):
SELECT * FROM users
WHERE meta_data->"$.first_name" = 'bob'
You might notice your json data results are "quoted". You could use JSON_UNQUOTE, or you could use this, which is a shortcut of JSON_EXTRACT & JSON_UNQUOTE:
SELECT meta_data->>"$.first_name" FROM users
WHERE meta_data->>"$.first_name" IS NOT NULL
And to select data from within sub objects:
SELECT meta_data->>"$.address.tel" FROM users
WHERE meta_data->>"$.address.street" = "123 Main St"
docs: https://dev.mysql.com/doc/refman/5.7/en/json-search-functions.html