SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2038e1c8ac8fd0d67c99964c0c115dc7d94204540952fea2c4f8481f8992d936' 
  AND token = '2NMTsqS3UZrTAzewjq2e8LI9waMSNXTDOmwWrxd6Lrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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