SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95a091a853f82e5134290f69fd3658cc9071407aa52edcf291bf226c91956034' 
  AND token = 'UumybieJGdPOEnp7vCobsdouzjJD9B3XNMqo+Ks2K0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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