SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a01f3e63f0dcb5415e0a76ce354597f7a2c456cad291e5f02e2522fb10d89018' 
  AND token = 'lk2sXLPBr/BQivlIHj7ZmOMKfzc+exUqP8MrpKY5t3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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