SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c4809a484a11ab41274996e7f5c6256d323fb75ed58bbcede2661f109027dd3' 
  AND token = 'MyKZQuMdjZmz5qF1144eqBSPCDjyMsj3APu955ve/h4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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