SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c195fcce29838b9bc7aef23c3753309a5326c56c5a94e0f0e707a634b660cdc' 
  AND token = 'IKleDFDx5fSgdH9N518zgpY4KFQwhZHfHkxK8ISwmCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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