SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '233875c08bf2f7855f969b38f164f37c612a938f788e383833b8592056624376' 
  AND token = 'wTusOU9yiivyxt+NPY5dvfloW0P6uaWVGNCM/wzjAJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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