SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9d6bd1f72a006f7e06f283d197868d5f9de429c999073e277c73642149d6e894' 
  AND token = 'Fqex+GCRDYacpWfXeZlozYkWAVTMt5nPQ/NFw7VJ0Pc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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