SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63586895db328703d273ac728e8a6a8b14e3bb1768252e72c6ee17991da7e2fc' 
  AND token = 'ubzx6WojyoaM2BsavIi9OygZcviCfqn81QyuQ9bEqt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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