SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd663349e23cd94afaf75dad006922599e736dd99cba6a258c2a09ad0eea4c9e7' 
  AND token = 'iIXPgIjbNShFtfHEbRB7W/XpMqX9n57hqJUR5rDVZQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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