SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf86ae773d7bcae1ffeea587ee73d6de0423ea53c7b0134469354fe9f3e1e433' 
  AND token = 'cWJPwwQLNlEAnUaM5lkDEvq0kBSgTlQOb0jgc0zZ9R0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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