SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aad45c54a47edf04287470983352c5b2d044a27b7910543bbfb327fe73157196' 
  AND token = 'CrOjcmD2hReFsY1FniJhXzfUhY71ZBRga31hUBg6n+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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