SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84eef7c86029b8df11a6b1fcd882d37a8c5346e54bdbfc197e69619463514ef6' 
  AND token = 'XxMZkxQSVG5w7kwn6kiPAqDWqpxHtB/T3j7jgahiJSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}