SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b1a9889294c19d655e838f1ac14f28a693b971faed8ceb49421a36e61f3c326f' 
  AND token = 'Dip2TjxGNnYVWsQa4fOUoYyM650fwzZGktXBW5O5FDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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