SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4b6f44e84993669cd2b5fef67afe57604d26e3e5bf10ce8f868630af5bd9437' 
  AND token = 'TaIFJnkMs/Mud3/LLhud10YPrHQl8CqKMNA7Vm9vWL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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