SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f8eb5f11d7322a78b6bf93c584f7c9df8d9546a312c51adb6ea87a4ea72fe91b' 
  AND token = 'yuB35bsgZN7/ja9J4Z+VKLL7GElAIXmLw8YcPSiEaCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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