SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5255ff3a51673d83c6ef662753b8363ed09450d7a963e2173033e3c583858ce7' 
  AND token = 'hWvuRlQr19P0JsU1BdzRR4DHIdQNjQXYsfNO4Rkwxqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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