SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47c4d4962c7671d989492f35417ce323d2f625a161673684dddd0259eb591923' 
  AND token = 'QZAdMfnwJknICv0IN50MgwsSxK390qB+2g2E9Ns18is=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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