SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '548f63d9709867272bf3ec191ef0204614c2558cd31dce5fb8e559b841e33cb8' 
  AND token = 'YiGlzjlZHBkQfQwGkUvDcsF/FygL4aJjREzXr05gttc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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