SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8246933e198afc67fbb9b5e3911e728514853d5745d91284fea3818aaa036a7f' 
  AND token = '09t7siQb/4+uKfGrtYVNszXpPCHcMPPBMGs+VKd7jJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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