SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '85690ac99ec5fdc0faf4261628fca588f93818b443dad9ecc86cbb2d5d04d6de' 
  AND token = 'QTx4d9BljPTPWugmzU2rpR33UHlzTWhca3kdvSozHb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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