SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '74732a87bc00439e7c43faae87209ea6005071998305fd8f7016d33ad466b2b8' 
  AND token = 'DIW1lviBC3V7afhyFlPYEgVNvPRtMRSSKFtQH4j9iDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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