SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e01675115a84fc1c8688e6396cd31c50be168e03b35950a33c667524186ed47' 
  AND token = 'Arq6D3qyBEn9OWNKdXF3SaGdxdM/4SeWqKmLdZh2rCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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