SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8af2e7ee2640e949ee6212273e8cf25b7c6e58138d932688ef6e790d47a60f12' 
  AND token = 'fj+DRFCh50HuoiCFxdIt15cRnwDThiJN9gUb1mRUKog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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