SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0625c2ea2dbe04518ce3ea1146a3460923ff870ba2acc25b06a1bd5cfa5d114f' 
  AND token = '9PYkDsJiqEWqpsixDKNet59gOBVWwzuKjoDyARmnXRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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