SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '03f53c2887a922d9d6a97c54e1abef76f3099b5201dd90c1bdaded35ac94b49b' 
  AND token = 'V4Gpg8rHuTh1Ble+FmHm8ck6+DR6RVl3vaUFNE+8BtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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