SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80c7b5c80724e0337bc358b2bd4748536a782912fcd416078362534a62d63f04' 
  AND token = 'DlShLE0GZmV104qIrhGR6sYlb0Javb21GMM9XuuDwxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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