SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b4d48165abffff30020d268163465460479467615240277c4a7a35ad01ff7831' 
  AND token = 'kSFzXksBwLaKwTEGK3wpHZQh8GVklGZyh3MFUEvLjGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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