SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6544401cc7f1f0c8adbbcca05903ba7f45cbf0bf69cf520cc5478e684665e050' 
  AND token = 'DoEVnZUsujT2vj/LPx2uzsVK7yytJNAJLO1nHBdxlXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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