SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96982b01a97e63a0843baa8b5b6621e74228602724d52ce96dbecf62341cb979' 
  AND token = 'SB+gmzf1ofbhNcY7YLG5mPeEK5hXntMLrnOdDRtV9xg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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