SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9397d46e4100c0ff525cfe78448d5035bd4ef0ed0aecaaa675a6b750333e2e73' 
  AND token = 'qw/yS0J7EX5ethzl/EfqFCZGgDUEAMsiNnNSM1gGGL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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