SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25276ed692f8f6c2b8e30b89ee608e0a76baefd324d8b44558191ebbc0ef3085' 
  AND token = 'aYI8BWhaID9Pwaz6xVhvYHZ14uSbo0uKUCiu49Kgsqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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