SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '01ebe9bc6f3268a3d242476a5a1b2bdf7e183f519e68c982734dcc0899a176ec' 
  AND token = '8uGD338njV7ERyul5bt4Hsxw9XRHeBwnOK2AXjtWPVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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