SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a998eedba7f620561c40d0fd7686b23c3e73db1154bf7366d637b9f7a938e4b0' 
  AND token = '/C5o59FmNtuDljubr8DwfmiKoUMhXO6RV87FeQkgVzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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