SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59724c6c1cb8aaabd499f049f3eb332648e1727bc9dabf0a000dcd3eab45ff47' 
  AND token = 'Xxtr+z75t5QEYLwag6fKSe9LWdj94M7aeniyqw97rno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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