SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0645d8d1dbf266c5ad73536bbc85c200d294c043b302e9d63bba3bb1c587f1f1' 
  AND token = 'uTV/uOoLYMJC0QQnhZF1MYtSPl7juzDsqyF8XW9CEyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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