SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '02355932e73d92a0962831d415ec1d1b502823a671a2b4bbfc0c067b68c0fa4f' 
  AND token = 'vRzShOU+HigJdHreviU+NuYXl696awby3o/+Ekyq4iA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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