SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8b9220a48262031764f58d7f135f147f4dfc1333cab19ad59583554552a349dc' 
  AND token = 'zK2kyL2+YgiZR/crtjgB8rH6J+6wvrF4WypL289egkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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