SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89b100d5f5221ea63171570913b7c4ee0a32379602ced08f94ac79156b6bed5b' 
  AND token = 'SwhCYpeLBneCvP6djCQXu0SRCx4qifxtPBZEYHZTfRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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