SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6d4230d3a0e16e65b4f9ec8c83e170d7de38cb7e9c4b164661bbaefc7ae72a8' 
  AND token = 'pD3OtwdaYfy9giD/+cXP9SUzrDKXUQNRzhtSeTHwlg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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