SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01730c65d7d97861269739d27aadf9d4d5406a2010f6746a5860587000846c8b' 
  AND token = 'Fsy2RISYVSlgnr2LT5DZhA0ks/cJqiVrhUcUrbt/qvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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