SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e813400aa2512abd6a5ebdf69e6ec9ca3c49fa33a36cd3da9e93bf146daf221c' 
  AND token = '/otFvzlKOzTVBxNnfTjvNOkHArNcAYLDbwWjQ7QkYBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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