SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '620cb948e13fa507b23873d9a68f8824fa1b39b2d65209cb1a5205a3c35e2fe1' 
  AND token = 'aKlI2Ze0atxCIXyXYWmz78gd/bO3y7KwIVIm/qTyJk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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