SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'caf7fb0cb45990fe6a43137775f788b9c7552547eb568b7b15a913d0678c3623' 
  AND token = '84rnltxLIoK0ZlDhJEzGiQEiXsA0vMXJwzNdnWYa8P4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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