SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06f797f704f195813b7a26b6827bd00604dfe95a263f5d46b8c931b36f598645' 
  AND token = 'y0UbHJ/gFN0jTBKveL/qTcJpI1PdwSIIaAXkjWLlLP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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