SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a02805d1aef3ab2e5f2cc2407c0b43dd0ef8642472589ccaac7099334b05eab' 
  AND token = 'UznrZlmU+UDJvizgvC5GS2+dTQV2BuLnJAbg3fwgVwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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