Source

File: wp-admin/includes/class-wp-site-health.php

public function has_missed_cron() {
		if ( is_wp_error( $this->crons ) ) {
			return $this->crons;
		}

		foreach ( $this->crons as $id => $cron ) {
			if ( ( $cron->time - time() ) < $this->timeout_missed_cron ) {
				$this->last_missed_cron = $cron->hook;
				return true;
			}
		}

		return false;
	}