Add index for access_token (#21908)

The `token_last_eight` field has been used in `GetAccessTokenBySHA `:

models/auth/token.go

@@ -66,7 +66,7 @@ type AccessToken struct {
 	Token          string `xorm:"-"`
 	TokenHash      string `xorm:"UNIQUE"` // sha256 of token
 	TokenSalt      string
-	TokenLastEight string `xorm:"token_last_eight"`
+	TokenLastEight string `xorm:"INDEX token_last_eight"`
 
 	CreatedUnix       timeutil.TimeStamp `xorm:"INDEX created"`
 	UpdatedUnix       timeutil.TimeStamp `xorm:"INDEX updated"`

models/migrations/migrations.go

@@ -441,6 +441,8 @@ var migrations = []Migration{
 	NewMigration("Add header_authorization_encrypted column to webhook table", v1_19.AddHeaderAuthorizationEncryptedColWebhook),
 	// v234 -> v235
 	NewMigration("Add package cleanup rule table", v1_19.CreatePackageCleanupRuleTable),
+	// v235 -> v236
+	NewMigration("Add index for access_token", v1_19.AddIndexForAccessToken),
 }
 
 // GetCurrentDBVersion returns the current db version

models/migrations/v1_19/v235.go

@@ -0,0 +1,17 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package v1_19 //nolint
+
+import (
+	"xorm.io/xorm"
+)
+
+func AddIndexForAccessToken(x *xorm.Engine) error {
+	type AccessToken struct {
+		TokenLastEight string `xorm:"INDEX token_last_eight"`
+	}
+
+	return x.Sync(new(AccessToken))
+}