SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47f5b7af33d75a62cfb7641d2ac981ea51a479691406fc9d167877e1b1e27310' 
  AND token = 'N/z5xzHuYRGp/sK6sUeB/XYmP6MJ1AgJp3RzKKTunFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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