SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04894513c559a8e7cc51a9019e2f0a2f65709eb959565c264c6e9df94f1fd901' 
  AND token = 'C5gaHre1tIqLqcU99xXwZXCDxAmahdZYGlWQ/2taa9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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