SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a9cd7767c56dc58b86c63038f7d2ed16cfb47e51ff2dfd11cc81ad2d84c5010' 
  AND token = 'Gq6Pg3DlkVir+UGYXOu7bGboLUO0QsXQLUKteefif+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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