SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f41019e5dd14c9a488c84ecd965b0224a0e03806b1913c7500e31ce559f96d29' 
  AND token = 'rb/3HYf0GR+WSdkLvYfapbmQgUcpSGfAlUwrrcYvVH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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