SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd595e8c9b95fe268bb10720b40aaf04ec576ef4e26d4b911d6250df6b8b0283d' 
  AND token = '/imzVqxYcnKobBPnHdNOIJZGHH2uMpEJV+YMpVIssMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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