SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaa938abbd65444df4fc9915f038e98f65bbbfa9459c56446457f28aff53d752' 
  AND token = 'xbkQX211xqcBEG/3voju6ZvDxjN2ZRlWgQGTU9aotQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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