SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dad65a34cc518f3bb6578047cfe337f060d279e3fbc4886485620184eba8efc2' 
  AND token = 'iR8hqa6ZE9l2nZj0dkezTgx1QCDPGLcOfjSjRzc7iTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}