SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22c91b635afafd2728a842523828dda8a2add9acf8a4c1c833a25b0b2dcb70a3' 
  AND token = 'BUqIKtxsZUChVSfHqTlwms/kDlD+Dnt/hcBQotjkolw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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