SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f76c7dda5fe2812609c1a8f3a22632f2eb8fe7e9787c6ccb938f3e5adfd36880' 
  AND token = '/PfUC3dcugQq7gqjQHXz4e5ImritCFYuzGPxcBeaFWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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