SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1018e4d2e5e9a8c617443cd42bfc422e8707cdaf00a496105f2fe276210705f' 
  AND token = 'QbvhCEhZS+SJjHINTtSOviYnYhgfB1Lh2zbepoKe+ZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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