SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11766154140e087919630753f2465b4ce5ef1e4de607cff01e94d8864267fb6c' 
  AND token = '6uVgQ+CT/rkUNh5foz/3SZ6eArJEL/QYRyUBcCgG3U4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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