SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f182694abadb630860f2d86792dddfd4b8af1ff2eb1eeabfbaf85159f6014a8' 
  AND token = 'bVAio66ZsznK4F8ApT+RV1XzIWhEHnhzku2kYsVY1dY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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