SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bd24cfe5176e85177341a2ee0dd20c7d59ca08349b4bb111c30c6cc7fc2aeaa' 
  AND token = 'JXOxL8CUawOZ1ILHWH1EoEvmniEhJgF0YeVO5jdwwFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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