SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4d35e28cb19856c6dea31315a795c70feed569734bb407993de89fddc7a37ec' 
  AND token = 'Vwqls8IMyHIwXvl5nmhuIuJTZhsPR7Z6qg4OWBF3Dbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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