SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '403226f743eb17ba85dae91978ce3c78756629d844fba9dd8e62e43ff0ccf210' 
  AND token = 'nM4kcPHReRwMlQJLHZZCbMzsAesbDp/8ctDd2KBomzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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