SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b507ab87522ee9f587281ebe08323ed7d975af8afc9c1d577d223179892bdf5' 
  AND token = 'w+weHC8vQjEyNRSMIPvOMZUyXyD28RBUuJ0uN4dAbRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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