SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd78e6c1e8be9395ccb254566b154144be7d53493df90aa4cd5990155f876494' 
  AND token = '7nGnQa2FlgeRlrPVW3FWOUuurFzhPX7huWh9jtLKJ5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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