SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ef2c02be7824a60cf747acc9c08efaabf48fb50ff0a6b2ea28991ccf332707b7' 
  AND token = 'm1es9WL668oLAxv+oy+wjtEf11fjG+bsoKjuh+kiMNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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