SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '034d716f73a04ba4a6a79ba76836a59cd85c57c92b7330fa8a689acba0ee088b' 
  AND token = 'zL8PCEMnVaoeAo5AgoCl4dBQWbSt6R00lLPhCN7/hyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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