SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '192cb835429c280572c202b0a7484b4f83514fa9a0d8928c619fceae0d9d82c3' 
  AND token = '139qeNLBG0jx6GWihAufuO7J8Vv6O16FZatvOn39Mq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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