SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4eb8d7fb8146f4e7219da2658cf13c8895909b8913be8c18fab75de9b0f337b' 
  AND token = 'W1FAlC6JXJW4HI+aCuETczgPhNWWUTZkKkvrm4E5/yU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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