SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '147de54c4937f29ae83ff358f4dff540745c5fc8c31c013611de9aaa3489a213' 
  AND token = 'ox+yULOky/NwmoRfNwnayis4yTD0XeN/eWYnamOqHjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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