SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24e59534950ade19acb479f874badfbd918047e81b0714913edc0c267194ff6a' 
  AND token = 'MwD132XVXqSKQfRByEYjHMec4gLSQzokqxnhf0DYjEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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