SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9efa2b9931bcec7663224705bfb455ba4de9d1ee68d069eca4c0ed3a1094e857' 
  AND token = 'rD9S2Ts6MOcw8dkSvLtsQi9NXLOc6/cJtrIWilmaqKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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