SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16fae0d5e38b82dd7762f71737fe3c7af56b75a9617c1f202ab68d13d6648698' 
  AND token = 'DCQeHgsRVjNJUIXmC/wxVaJLV3ROoNh2ONK0+ZfJuwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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