SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c99911f77958a6f49c5ebf16d6cef90752787e841e938bc6f80939a64a7f771' 
  AND token = 'x3DxWf2ae97jx5bTRU/m1bdQKXKSP41wOt/aGEkfWdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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