SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '893af88683fe52cb9231f65fcd1f244cb46bf406bd41a74c308c4fc53eb1ba6d' 
  AND token = '9cHbs4ynA3mu5YFOGO3/4zgiaJ85+o3J35zMJttsD5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}