SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c2e4a2b19c3fb1cdb577709ffe8d833656580b2da6964b8f8fc74220b8ab346' 
  AND token = 'SjVvQA0vYbMvazCf7g2ZDEz7FSCA4H/YTjeNFo/Foug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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