SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dff2bff2a8b2c884966c9f9262b4bc84122020793839f56f37d2da6d35525aad' 
  AND token = 'pzOXLnOcaBYbxYBO8u0m/IC/KhBCBHlgp+AQDejtqCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}