SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4f690930e82412c8e45ae4e7269edf219fba0fde5df31dfa0ed5c462aff8838' 
  AND token = 'UfX5ocwnbG1SuTthQ/Tn9O55M7ISTldonoNUqz0+6os=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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