SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40d114f2ba12a617d9db9a37d623cd7096318710db1e5d7e5263b5418e4ae086' 
  AND token = 'WXCo3blbjYl5LxmT56FeSWvWEEMNx/FfC5JDLrUKzLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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