SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5c6ec38152e7a10b16d1a368dd20b166038dc7aab62e3e17da31ed73a8604778' 
  AND token = 'iD5zdPYMFz6o38R0mk19y1fdavH3bxlMkUvb+P49zVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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