SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd48acfaa4df1a09c721407961ab853b9d7817d76081a29b399b9021472bc52ea' 
  AND token = 'VO1m6qxOFpwgQ6MMeJaV8fkUHAHgTZsZPICEpOFLxKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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