SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '957b7b875a319aa8aea34d5019871418093d4714d79a674c94706e007cd8d719' 
  AND token = 'KGxt6M4+Xr0zwPbOtt4g+ehKkjRnK7kguvj71TaXMVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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