SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1417946fd1972c2348203e02457f32c0e974f92f5987b5320a48409b467dd7df' 
  AND token = '3NQB9KH+d8iwS6/GzGZRUoatgHGvWZm+6IVKUBg+y20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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