SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1933f76d34672592e6ed0ab83d6d5b91457fceb7524a558ef3b6afe68c05ef31' 
  AND token = 'YbkTlH1ih6udmCywR4iYOwAHZXRJxf8nOXq7L7+/IBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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