SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2779e354740f4c587f9a1d2d5d8e7ca5be0b357c7f1f2cd379408081c89c0174' 
  AND token = 'iuof6oCvndWDzpf+sAP8PCXwlGbK9kZvZseJjgJvWpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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