Instance

LimeSurvey version: Versión 5.6.31+230718
Own server or LimeSurvey hosting: CentOS Linux release 7.9.2009 (Core)
MySQL 8
More than 4000 active surveys
More than 700 users

Issue

We have a problem with MySQL database since few days, and we have had to close the user access because this server database serves other MYSQL databases and therefore the applications that depend on those other databases stopped working.
Example of one of this queries:

# Time: 2024-02-08T08:08:48.649817+01:00
# User@Host: xxxxxxxx[xxxxxxx] @  [xxx.xxx.xxx.xxx]  Id:  3744
# Query_time: 20.822056  Lock_time: 0.000163 Rows_sent: 57  Rows_examined: 774187
use limesurvey;
SET timestamp=1707376128;
SELECT a.qid, a.code, l.answer, a.scale_id, a.assessment_value FROM lime_answers AS a JOIN lime_questions q on a.qid=q.qid JOIN lime_answer_l10ns l on l.aid=a.aid WHERE  1=1 and a.qid = q.qid and q.sid = 351814 and l.language='es' ORDER BY a.qid, a.scale_id, a.sortorder;

Only with two surveys , several answers almost at the same time, and about 80 queries, crash the MySql database server which is on a different server than where limesurvey is installed.