SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afb0ef33c3173a0eed0079e0dc9141ca56f720af9d9d9b4f5607cc551942fe36' 
  AND token = 'AbVk3XOLcoIwo4NEmUXgHD6nkwBFgnFq7qn+B9/JVmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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