SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10b49c99c7040060ca61931276edef5f850301a702811cab61b74f6baa36ebdb' 
  AND token = 'uWuYL6IS95L+MQv1CzigT0STxmXGBjmRBrJtFZatzJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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