SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '264a968e131085d63de894853c5b6d6bf4a9c08ae1e4c1d1152100b00a172192' 
  AND token = 'sBkv7CJqajnKE29bLvmTYWDZj1ll0j6IQGWCTQwaXDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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