SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39be4cd190cb949308e3dc20114cc90041e5110b922d46d66b01e0545a0e177a' 
  AND token = 'OF9lFT/iIJShJAGgNj3L86JZNShp2mcznVJU5zunRvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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