SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '814297cbb3a493307f003a35442524d347134cc2d481da7a7d574916c449684b' 
  AND token = 'Kx3XKVzKNI/z6zzs/z6dOldpAjlamOHZBlzUsRssTs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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