SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7828238de89325f838a1ac20c3e570164152291183e407b24d56926577e05b7f' 
  AND token = 'YuD87gpEYVdilxTk5XV8J5ZFLSOc/qGz9croviJ6zfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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