SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa9edc1b650ccb6d36b49445018e82efaa4f7605dbe771844ea1d17d7fb7a70b' 
  AND token = 'KVIv63MCPpvYYKd9zVc50rpkN+Wh1TSUZPTsgUopZlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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