SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd96a339030eaa4fff7aeb8fc4b206dda7888141f3d118cca2cb410dd2271dd03' 
  AND token = 'PaOdSmx7ePdgyZKgv/lxNgQ64Db+7T8nTuEjFOGHq30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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