SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6ec6f1d66e5bf5ae2b493766df180316a4f631bbfb4f7d1568af16de9a8ca33' 
  AND token = 'GbP8FpyvefintVzOJFNcoBQAwNLjzUIyIJS06lCsHoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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