SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67026b23cfed0d7452d75039cc0b13d5856e74dc32bdfd51763446f32b567d3f' 
  AND token = '8HZE4Euctc2DWwGuBywmkBE9ZsJRIx5smOvD8iQoHZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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