SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e320aa438c8ede2cea1cf9df039b08e41a988f21190447706ab8d306f987d24c' 
  AND token = 'd+vwsHRCYXkXfsc2V5lkUNE88AJHFPVvwcoiwAB7fx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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