SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26f45b6f66f037b7230883f8855dcb004a27477bf5affcb512267af650f64919' 
  AND token = 'wGXjiwrQokrWIg3xlnA58UTbDYgh2KmaYVrlPRKKmdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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