SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f26213256b84dda3d0f30e7914395605012ad6f9e2ed3bc4bb6a3f4f8f128056' 
  AND token = '+few5G8jrblsqTTlWOodVvwn4PNoUysMqgGVGFaFSAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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