SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '392dba808d52b951949aeac9be42cc9a7bd7faeb36ca96a92e06c169dbe2d1c5' 
  AND token = 'rGtfoNuACSbWdbCOHlFVe2Jh0bWvkUgIAaw6lYJ4usI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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