SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3de916f3ba9dc681b166103bf2fa244940bc73122c7d93a5d9620ce67572929d' 
  AND token = 'DWya0obPXeZx+hoDzanFkkO0a2zOKSnFJCTt9bypqvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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