SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61fc2d3ce2e51f133f594bad566da1b6ec1fd48580fa451549ec921067f7d7dd' 
  AND token = 'HalFLl/WmGlEmB71gUCc4FOxV6mDCcwzAPu/RVKP8tA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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