SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '663fc7c638ea01e4bf7db52c80acdcc0780bda0878634be1843b591c699acaba' 
  AND token = 'e1/oRFRXCilT/kHAF9KwjRt4wZamf2riC6YMU6RQpwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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