SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e31a720a6a064c4ea224d878cdda3d4ed9a1629403968ca5744830b1ad67ff1' 
  AND token = 'PXB/1aCwlB95elmzg6teN+e2oRFiJbJx0SM5mIDr/zU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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