SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '241f01fd59675676f3c856099d01fbf4ae7835ff180b537f804f401c4b5b6c3c' 
  AND token = 'QX/IJGjWIHlNeLgubBVNVyhqCBEki2rwN0xwYzyvJOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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