Problem with MYSQL Load CPU

I have a problem with a site on my server. The site takes a long time to read large tables (with 200,000 records), and does not save as well. Cloud Digital Ocean 8 GB RAM 4 CPU SSD DISK my.cnf file [mysqld] performance-schema=0 join_buffer_size = 6900M datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid innodb_buffer_pool_size=25165824 max_allowed_packet=524288000 open_files_limit=80000 default-storage-engine=MyISAM #innodb_file_per_table=4 sql_mode=NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION key_buffer_size = 256M query_cache_size = 256M tmp_table_size = 512M innodb_buffer_pool_size = 2048M innodb_log_file_size = 256M max_connections = 250 sort_buffer_size = 8M query_cache_size = 0 query_cache_type = 0 query_cache_limit = 5M performance_schema = ON max_heap_table_size = 512M innodb_buffer_pool_instances = 2
mysqladmin pr|awk -F "|" '{ print $3 }'|grep _|sort|uniq -c|sort -n 30 riscozero_us
[root@eua50 ~]# mysqladmin proc status +------+--------------+-----------+--------------+---------+------+--------------+------------------------------------------------------------------------------------------------------+ | Id | User | Host | db | Command | Time | State | Info | +------+--------------+-----------+--------------+---------+------+--------------+------------------------------------------------------------------------------------------------------+ | 546 | riscozero_us | localhost | riscozero_db | Sleep | 106 | | | | 548 | riscozero_us | localhost | riscozero_db | Sleep | 921 | | | | 551 | riscozero_us | localhost | riscozero_db | Sleep | 115 | | | | 553 | riscozero_us | localhost | riscozero_db | Sleep | 1 | | | | 555 | riscozero_us | localhost | riscozero_db | Sleep | 1 | | | | 558 | riscozero_us | localhost | riscozero_db | Sleep | 236 | | | | 560 | riscozero_us | localhost | riscozero_db | Sleep | 879 | | | | 563 | riscozero_us | localhost | riscozero_db | Sleep | 162 | | | | 566 | riscozero_us | localhost | riscozero_db | Sleep | 607 | | | | 567 | riscozero_us | localhost | riscozero_db | Sleep | 541 | | | | 569 | riscozero_us | localhost | riscozero_db | Sleep | 568 | | | | 575 | riscozero_us | localhost | riscozero_db | Sleep | 928 | | | | 576 | riscozero_us | localhost | riscozero_db | Sleep | 0 | | | | 583 | riscozero_us | localhost | riscozero_db | Sleep | 550 | | | | 584 | riscozero_us | localhost | riscozero_db | Sleep | 570 | | | | 652 | riscozero_us | localhost | riscozero_db | Sleep | 1 | | | | 665 | riscozero_us | localhost | riscozero_db | Query | 2 | Sending data | SELECT * FROM cadastros, inscricoes where inscricoes.evento='829' and inscricoes.cpf=cadastros.cpfa | | 666 | riscozero_us | localhost | riscozero_db | Sleep | 2 | | | | 668 | riscozero_us | localhost | riscozero_db | Sleep | 886 | | | | 670 | riscozero_us | localhost | riscozero_db | Sleep | 134 | | | | 684 | riscozero_us | localhost | riscozero_db | Sleep | 537 | | | | 692 | riscozero_us | localhost | riscozero_db | Sleep | 72 | | | | 693 | riscozero_us | localhost | riscozero_db | Sleep | 1 | | | | 697 | riscozero_us | localhost | riscozero_db | Sleep | 491 | | | | 701 | riscozero_us | localhost | riscozero_db | Sleep | 121 | | | | 1095 | riscozero_us | localhost | riscozero_db | Query | 0 | Sending data | select * from cadastros where cpf='084.233.239-19' limit 1 | | 1109 | riscozero_us | localhost | riscozero_db | Query | 0 | Sending data | SELECT * FROM cadastros, inscricoes where inscricoes.evento='829' and inscricoes.cpf=cadastros.cpfa | | 1114 | riscozero_us | localhost | riscozero_db | Query | 0 | Sending data | SELECT * FROM cadastros, inscricoes where inscricoes.evento='578' and inscricoes.cpf=cadastros.cpfa | | 1118 | riscozero_us | localhost | riscozero_db | Query | 0 | Sending data | SELECT * FROM cadastros, inscricoes where inscricoes.evento='578' and inscricoes.cpf=cadastros.cpfa | | 1124 | riscozero_us | localhost | riscozero_db | Sleep | 2 | | | | 1129 | riscozero_us | localhost | riscozero_db | Query | 0 | Sending data | SELECT * FROM cadastros, inscricoes where inscricoes.evento='578' and inscricoes.cpf=cadastros.cpfa | | 1131 | root | localhost | | Query | 0 | starting | show processlist | +------+--------------+-----------+--------------+---------+------+--------------+------------------------------------------------------------------------------------------------------+ Uptime: 2111 Threads: 32 Questions: 212525 Slow queries: 0 Opens: 2432 Flush tables: 1 Open tables: 1412 Queries per second avg: 100.675
Load do servidor Pid Owner Priority CPU % Memory % Command 1718 (Trace) (Kill) mysql 0 259.98 7.98 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid