SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8136d88f26a377984f68d908dff553d93926d53d4df1f67bb6610ee4beb5c8a0' 
  AND token = 'rZpb0XbDOUMRrOFVhNL1BqqcktISTkT6vRaVH/AwZQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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