SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3fd4a905f0e5543b67193f9da1136bad5596017d24fde7fbc6263f436b07cc5d' 
  AND token = 'naLEXZYQk0wOimWJky3L+OkWpr/qRvzVUZQktabYylk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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