SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36bcc6fa5572b8f916a230182f6fd77a282b5a783ee23a5f7185469153446a89' 
  AND token = 'yAz0m0GhIwL9FgYJPmsGeVK4WaTuM5Wqc9EumFTcFOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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