SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98079d04f192024890d6cafb946a2080ea82a827d9fe390214af51521d867a9d' 
  AND token = 'woS2mkC9KKuptaY1WhtZRjMTvESVC9zSoXRZgQrAh6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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