SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '740d403af5892a3b304f4059ddb8899e05471e055753dacca855702243ad3f6f' 
  AND token = 'IeZ79nN1ilO9MI4FgBz2DEzlF063Qy6qHUZUsP9tiac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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