SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eca5c0eb1f8f694aa372630466562d5329874fcb098b7b205b621cf5a83c778b' 
  AND token = 'VpZzoBtiObsoZMLNZrVUvexfHJGVYqHhGEykjG+yLFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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