Slow query after the number of leads is greater than 150000 records

As the title says, I have more than a hundred people using the system at the same time, each time showing a list of 20 records, at the critical time for telesale to work, the system often queries for a long time (up to several minutes for 1 visit to the lead list)
I look forward to learning ways to improve system performance.

  • Server: Localhost via UNIX socket
  • Server type: MariaDB
  • Server version: 10.1.44-MariaDB-0ubuntu0.18.04.1 - Ubuntu 18.04
  • Protocol version: 10
  • User: scrm@localhost
  • Server charset: UTF-8 Unicode (utf8)
    Apache/2.4.29 (Ubuntu)
    PHP version:

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