SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69f5d89de448286a41c5c215ff37f1cacdedca2f13008ef350171b60dc171a13' 
  AND token = 'UwNI4XXhmVH+PEVZt9uoPgMih4YgITpnuJMvljj5AMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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