SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11ed55ad36654a9ded2e1cf155c77549795a733381b503f4d2081558571a8947' 
  AND token = 'lWfBpJpg+GH+UbXZlmzb6b/JDretXYJBT7v9N8feyZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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