SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '206b1a8224a152afe30644b3eade51bfb0378b365cc9f02ad56f529508e0ca23' 
  AND token = '8es7wniRNmQ29AnK2Kcz0C6pbIbk/yA47bAjwCzXHqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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