SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30dcf165a439882ac075a6137985a6f685fa0150006b52fd3cd7e4e58d4c1a1b' 
  AND token = '2EB6AjDtz7583wZSaA/yy8FwXuLKM53jSKVYf12PRFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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