SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3fc0dccc99b1188b178c054a9a4354c63886334c5a5b25bf79cc30d610c2543d' 
  AND token = '4ndtVNLq/VEWG2A4E1WvOJYuDyzYVZ4uydZkbJmHuLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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