diff --git a/src/wp-admin/includes/class-wp-upgrader.php b/src/wp-admin/includes/class-wp-upgrader.php
index 695ce50bf0d7e..6299c66a5faef 100644
--- a/src/wp-admin/includes/class-wp-upgrader.php
+++ b/src/wp-admin/includes/class-wp-upgrader.php
@@ -1064,6 +1064,22 @@ public static function create_lock( $lock_name, $release_timeout = null ) {
 		// Try to lock.
 		$lock_result = $wpdb->query( $wpdb->prepare( "INSERT IGNORE INTO `$wpdb->options` ( `option_name`, `option_value`, `autoload` ) VALUES (%s, %s, 'off') /* LOCK */", $lock_option, time() ) );
 
+		/*
+		 * Invalidate the notoptions cache for the lock option.
+		 *
+		 * The lock is created with a direct INSERT IGNORE query, bypassing the
+		 * Options API. This means the notoptions cache may still contain a stale
+		 * entry for this option (added when the option previously did not exist),
+		 * causing get_option() to return false without querying the database.
+		 *
+		 * @see https://core.trac.wordpress.org/ticket/64080
+		 */
+		$notoptions = wp_cache_get( 'notoptions', 'options' );
+		if ( is_array( $notoptions ) && isset( $notoptions[ $lock_option ] ) ) {
+			unset( $notoptions[ $lock_option ] );
+			wp_cache_set( 'notoptions', $notoptions, 'options' );
+		}
+
 		if ( ! $lock_result ) {
 			$lock_result = get_option( $lock_option );
 
diff --git a/tests/phpunit/tests/admin/wpUpgrader.php b/tests/phpunit/tests/admin/wpUpgrader.php
index ffea594ae87bc..1df8416c63dbf 100644
--- a/tests/phpunit/tests/admin/wpUpgrader.php
+++ b/tests/phpunit/tests/admin/wpUpgrader.php
@@ -1598,6 +1598,27 @@ public function test_release_lock_should_remove_lock_option() {
 		$this->assertNotSame( 'content', get_option( 'lock.lock' ) );
 	}
 
+	/**
+	 * Tests that `WP_Upgrader::create_lock()` invalidates stale notoptions cache
+	 * so that expired locks can be detected and re-created.
+	 *
+	 * @ticket 64080
+	 *
+	 * @covers WP_Upgrader::create_lock
+	 */
+	public function test_create_lock_should_invalidate_stale_notoptions_cache() {
+		// Prime notoptions cache by requesting the non-existent lock option.
+		get_option( 'test.lock' );
+
+		$this->assertTrue( WP_Upgrader::create_lock( 'test' ), 'create_lock() should succeed despite stale notoptions cache.' );
+		$this->assertNotFalse( get_option( 'test.lock' ), 'get_option() should return the lock timestamp after create_lock().' );
+
+		update_option( 'test.lock', time() - 10 );
+		$this->assertTrue( WP_Upgrader::create_lock( 'test', 5 ), 'Expired lock should be released and re-created.' );
+
+		WP_Upgrader::release_lock( 'test' );
+	}
+
 	/**
 	 * Tests that `WP_Upgrader::download_package()` returns early when
 	 * the 'upgrader_pre_download' filter returns a non-false value.