SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd399ca31e25ac729f28434813c9a722a84f95c6f61ae3353e6b0787f5cf2638f' 
  AND token = 'wIGEJ7tgt504MgBGqSgweuDDbWtMiZUhDBCFEwASfZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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