SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36e49f822258dddf7fe35481ec7ea7c615badc63040645bd46df06ac9a0f1883' 
  AND token = 'qh6hYyL0Ldk9rh+wNaVlyjkpzy/7K1EIBvRj22hihHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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