SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f5b4ba4c71b69f506332cc8de5815a77d53ba97e83df79de81c0348d23d9022' 
  AND token = 'kJFhgANNpHEUPvYervJO+WS4yNQS9qF0DRugYBqQoKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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