SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbaaafc4535b5a871c3e587736f0e021de47bd48662879fa97ec9532aab8e0d4' 
  AND token = 'EsxIYJY/XIpdTOhkXLaJGb87ReQKYwTcoPsVOE2AhCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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