SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74d1f010f3c3aaaa368131e19826f8ff56a794fadcea575456a444b4604123d4' 
  AND token = 'iTJKr+bLsNIz/+oqQghSfVvWJ99uBTK0QCB77BL69y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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