SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85b3b6cdd2f3eb8e5f388fe71a4e5bc3c9f43e50a9f742a1c99db276e4d0bb70' 
  AND token = 'YySZgvPnBrsqCncsp2vGJYx1WxhTbibPgVxkUoHWRfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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