SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '45fa7daf4840cfb2d10e85aad7edb50f5dc40b5d22e33b53c6f6dfe7e647c59c' 
  AND token = 'UvPzhXYLSkM/h5cyPlPVjuhbKEkyfUSopg4IfuT2IYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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