SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb1f46562982e979a02a150f86d8599a0d867568673d8ce7d0fc248616bd79d3' 
  AND token = 'FGyeocYsVS53Zg5LlrraO6VnWxLmZAgN0V2k8Z57Isg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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