SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07e08d79dd19d242da76873fbde623cf1d4caccb78c4f6fb6d278843965f93de' 
  AND token = '7U8Dy1yXgOlSOqmydAa+7pXf2m/KTVWCoPCFuhiY0M8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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