SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd99d17e0cba76577810f7f4a121fb53b256902e4cfd3312605f1097909b88428' 
  AND token = 'JG4HNUxJhG6EHhe3olMT+wSpr53A4+qF2Ejwu1CJLqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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