SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96ea279429096956add2c7f1233d451cfd0244f605515514d7ef934f66c12f53' 
  AND token = 'nXMvygbi4b/XhDuPilnybqGJtHQxhH6VgzRGh7yxkvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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