Block slow performance queries from wordpress core

core_query_bans.php

add_filter( 'query', 'sel_filter_slow_query', 999 );
function sel_filter_slow_query( $query ) {
  //set an array of functions which run the slow queries: 
  $banned_functions = array ( 'count_users','bbp_get_statistics', 'bpbbpst_support_statistics' );
  
  foreach($banned_functions as $banned_function){ 
    if ( in_array( $banned_function , wp_list_pluck( debug_backtrace(), 'function' ) ) ) {
      return "SELECT 1 ";
    }
  }

  return $query;
}