SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20fd7142e7dad9750ceb3db76a3ea090f8d564d31402c5c3567dc3489364e581' 
  AND token = 'v3naTu3JAe4kgwjzxtqBTLoXYurYNUiMncmwG3JDlDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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