SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4988263a61d078b36590558fb3c439b40661dcf8c36063a1160a8428156e6156' 
  AND token = 'K3XMaT6BZoOPUMhKfpLtRIAGXrjL6qUzdrU3qs1x37A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}