SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '361833fde85fda8a820ffde4fc485185a42fe526ca7ebd7e40a61335f95f5691' 
  AND token = '0QERu+xAt3XLhSzLz+x7f2UCmzzy01W9DPztqiObup4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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