SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a56b79ae57a75f46b82071c13d4a0dececbea5b30bd138bc58b11706a7300d9' 
  AND token = 'EeeLmJOZ0lu/Py+sHzr48xogK0CkZVtl1GgE3qWSjVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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