SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67b47802255596d15b0923ab1f1cf71863e1d682fc42cab7b3988d9917ccf96c' 
  AND token = 'azku/nE+JQFnTVdGQyzcHnqWMNQj6CLJXV3I3j8jRI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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