SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f592eaa5c318b7047cf976a98058136a75b3b1689b83c8b0ea509f2b5561012' 
  AND token = 'wb+86u+EOhbGNZtogxvZgmkuEtOHHIQdKO9ysGTdF98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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