SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6100496fe475c3cb8fa99c1516638edf677885bf08bfb6557dd5a97ab1b44e0' 
  AND token = 'd4f1KVUtJBiu6q+CoUSDaIyVVnqGoT9qBKtZlPFmHwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}