SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '909fa04da90092cafb11ebea9769547940af1c13a2bfe18ed9f93fb55be25ad6' 
  AND token = 'sok8fLtIuUWPx8z93AovHXgnQcnrCoAcyVZcneMzWYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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