SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f38e5fa172f8b4789bfb56114c3ccc666dedb1e771ac1e8082c528fcac192c35' 
  AND token = 'Dp89JpWODz7HzgshQTFwZ8yikelLjIt0GlDHlfbxTRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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