SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8163334f22a82dbd70d0d0b75fffadefc48c41d64d5f7b0b528a567120988849' 
  AND token = 'KwekNB1XirSePQl8R1WHtiM87QZPmOOJ2csk0vHjVwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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