SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93f1656e46d84135beec8b65fa786656081e19c1e21351d9b2e34ffc860820c5' 
  AND token = 'Cc6CXJdniTpYUm8G7CFv8s39NJ2BLl8NAmQPo7ansnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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