SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '675a26e6b280adf0482a7409f5cdc801b9e94ad55c48d3fdde63db066ebd1648' 
  AND token = 'OUEzOjxK82JhGa2nLes8ZdqaXJBj7oVXsxQl8tZSV2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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