SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fc4b207d1cefdebefc805cba2dc017029975f3a641969d5c2f4e7f4a44aad23' 
  AND token = 'DgFpbWnaWsk7JirBAWIj0Ta1oXHxYsGDqPqy1VWrJR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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