SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3216b2048d9aae0cd2da7e8e1eb5c85a414f2871230d52510455107e073c57c' 
  AND token = 'v+pIg8fceX34MPrd6z7UAFYsjWmGKDiezpA8YfmMoxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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