SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f2954a833da6c5d7a6bc379fa3e0df6ff600f1cc99efadb2daab74164f3b515' 
  AND token = 'BULjiPIsU/vXzP3q1YmPLnB7OrVv3TIG5JzuIkJqBzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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