SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08cbd9a6997bed2b5af3670cefbea85f8fe2024aeaaf7a71e799d8a487586cf3' 
  AND token = '2YGNHNMp0HEKKfHMdfP1CbjgXEK+lesxdwT0huu1wsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}