SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cadb3cb39e257ffff9925829bda21fc1cadbeb36cf52fa81aac1f91ed866342a' 
  AND token = 'LgMnwRXhI9qCUIFBtd/wk7U7sCt3OgulOpfwxVjpDWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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