я вот только до такого додумался
select * from t;
+-------------------------------------------------------------------------+
| u |
+-------------------------------------------------------------------------+
| [{"name": "Tomas", "user_id": "52"}, {"name": "John", "user_id": "59"}] |
+-------------------------------------------------------------------------+
1 row in set (0.00 sec)
SELECT JSON_EXTRACT(u, REPLACE(REPLACE(JSON_SEARCH(u, 'one', '52'), 'user_id', 'name'), '"', '')) FROM t;
+--------------------------------------------------------------------------------------------+
| JSON_EXTRACT(u, REPLACE(REPLACE(JSON_SEARCH(u, 'one', '52'), 'user_id', 'name'), '"', '')) |
+--------------------------------------------------------------------------------------------+
| "Tomas" |
+--------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
