SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '518bfa345b8c7e74535b79201926fcea0a4ffc1d237721810df8225c4fd5ff98' 
  AND token = 'VdhmTTARHJBaQjOz8J1CKaFE6xgO7IY9JXbhGTHQqs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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