SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ae196181a52b99e2cb1433ee44a80aa045db7c93b52a15388cd31f015b162a96' 
  AND token = 'PLY8yq1HlLEYnRCnSC1X2jt/tcv+xldBvPJD1omtLbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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