SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f197ea1789656ec5f4ea1133a37a46a10312bb96e4072fbdc2d3e415fb30f1f' 
  AND token = 'FtVBjmkEZXS0NAS/tSyq2BTSPuAaKWBNeaaetUXGCIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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