SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9161262f7cc45df01309444dcfc3968e8ad049cdf86ca72f9b2adf006ea1bf3f' 
  AND token = 'Z9HCUzL9TfjHwUbn/zLyBzW6pK8ph9FwBrj+oJeJ6MM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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