SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99600cb2a34b889fe4ee5a04c564a322b2cd2cfeb988f2cd271409302598d04f' 
  AND token = 'Pl62ejrqjdaqcSscrH1MqmHAlZ6il5htcHuuM9Ib4+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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