SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '176eef41ad9b4fedde74f72957b2b07ee2810dc5817f4cc179afdacbccff1e5e' 
  AND token = 'lZMIcdpBIZ0GjPh/YNVC3uIsCS3hThehMzHtea6jt3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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