SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d61e910b9ba02a9a386209b6726c6579754da17bf24ac2e1e20906733a55875' 
  AND token = 'wdDzb4qgD0WCaS3xKObYE+fwuYJr+lmW9hCpLoA2qSs=' 
  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"
    }
  }
}