SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8574fe41b9b4a0b34a9389238ccb2449ea63433737f54a0dbc60f8b963c981aa' 
  AND token = 'XuUQIpd8qCuL+tKV6zXJsIJtfCQVskRvEx3qQv/vOpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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