SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6b607ca4def18b31a5fdd52bbb8b79a78e9e96ffa15ac6670a9194de838f27f4' 
  AND token = 'wuxG6yV87cwgKncwlFNfn6wjgYFSsEaVK7RBZpGWlm0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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