SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afd35aee860fecbadec265f9acec99e4bb07c884233552853804b9d71408b987' 
  AND token = 'bUOeVlkOlOcXxpiGp4GK3Xj2SJpYwMGy658z6O3LXGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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