SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73ee3cbbcf44aa18af6a8e93a959110ce0dc24ab1bebf6e36d45cbbfc385091d' 
  AND token = 'KaDwDNynK432HmEx9CkMkEb7cWKXiU6lvdvev3dEUBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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