SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b55f3789607fb9cfe9238faeec12326c18e049614de64a3bf58285b687ef728e' 
  AND token = 's1aW3FovYwf/QL+kWoVNlPz8NZ/rZoq9tvZ+yjptdAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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