SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f5980a566122a8adc878d0af3c0288ae940ba1e6eccb1cc9145b3c7f347db1a' 
  AND token = 'vybpatH8YRwvYJnbSuVNq7rCInBacqzQMq9AyJ10EpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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