SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ec42107d0c92056a0ee8863fabbca18d04655867fa473f9a2f0aa82dc0ba521' 
  AND token = 'OrofVm8yjjZJqDcqVJUf2kaDirTKPC2+pjB4l+/Otlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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