SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0baf867ede87589a88b84940318b253d1cc1a9d200b8bf6d23ff0ac6cca8172' 
  AND token = 'vnkcmdm8fSEMSZTZHWr20Jso6tLFW9M/ZA1KPDrQ5oU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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