SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16d0dbe0adc6dd37b3cb97b8002dad113f233c75f93500052bfb8a18d03ff0d4' 
  AND token = '6R8x5SQRJnlWPqfq1y679slDpDHbRN/HqM/hXUwQt9c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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