SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76c9958377bd0a846ef0dbeacd795b31d69640503112b67bca49a8eaf44fb07e' 
  AND token = 'ewh4cElGgk1bKFdBYeF0HrtYVWDd+j160Z7I/UWu0l4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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