SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'beef8966d15128028a91df87d7edc09a5ec07aa2ed31afdb2d03fc04da7abc1a' 
  AND token = 'Zh/+XghBYhQgLSlZigPcvayCA4l7PrB/vXizkLT5kFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}