SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4cad261d3121dc071e65a5fc25db9c6d4e7fdb25588cdc22291dae407ece6585' 
  AND token = 'eujocXTu2UEWpLy5B8veeezKdjYJ5B/Q1mLaBADKNj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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