SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f03e830e766da10cafa8896f6ceea8c7ad94112a3aa67d1ef616d5785fe6aee' 
  AND token = 'HCmWOyATEJZ78wRDE9i51daM21KKoGRRtJAgwTb4oxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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