SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9da08a6c08f1f3298634dc0ae752e99031eb4fc7295aa857aead20078c874fa8' 
  AND token = 'loAkk6C5knOvYeSxWOv/19xxAdRCAEkbCiDrjRIWNUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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