SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cd583719663074dfdbf3cb3e5a00a666762f34ac7c257b23f322cf6c5594154' 
  AND token = 'TXGR2Qq/HME+yr3jz2LzvPlaGGbeqz9ON8tsgBaA5vI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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