SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'efbe7435dc55b20d8428a7e95bc2c1f40b9b78922f47ad4c01fcb6978af9fa28' 
  AND token = 'akUn+dJ5zIrv/NruFYTAN67xbW/3xLwPg+DILoQzTrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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