SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d83007cbab0b689f505d66a5d2d4db819804147d2fb9843c4acbc1bca227f5c' 
  AND token = 'ttFHuWbd6g7qOTlzZk8jDBDSsOVQPP+PD5Va35YzJEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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