SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '95bc7abfc8546328d51093f80475d78356078e91433fc8c47754362f1afc84a7' 
  AND token = 'zyy+WMzwqMQlNNzYjmlTeePQAKQc77HHuIJRs9k9Vzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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