SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ceb76f699e7f87a76cc2051103f112cacbd0ec9367016a3efe5213244530a2b8' 
  AND token = '6Zu+yewCWU8CiFRuLdJ1XXvFWgzdldQmFGbRiv9jb+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}