SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d6f534059fe133b87799ee99aaa3fdebff23b3c10fa846e4efbad462d4bec87' 
  AND token = 'Elhfwmz18ysVmCjSw8NlLLA0SqndFGR1OCSx1DTU6LU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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