SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ffec0bfc2fe674e2e6ac33cef9950fbe3be525757dad1c86770eb0d4cb6c361' 
  AND token = 'nOePgM+OHGpBGqYftYrqKPG1gQXp7+vvRD8nzoTKGAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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