SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bdfc9fe75faedf5666242ecd40705c926d649db7fad8c48e0ddf100213f5b33' 
  AND token = '9iAxGKP4pobkUjoDZQFn/9Z1HmqsKgn7+wqEv/RLrvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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