SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd192d705646a675b6b2bf4c138c857f8737c3c8346284297d281c7542c6b8f13' 
  AND token = 'YSFQYzehANji5O+r49Xk1CXjB+24z5Ve6H4PniJ1vpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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