SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd80ac0ad12a86bf035aca22c84719000d934ab35d9efc34bb4b03b3c205a658c' 
  AND token = 'tbxReGPqZlyKizpC7QKPnCPUkqswhxqh2up8YVhXaHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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