SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d34630f7611e0b90b16774c0074df8769855f5f1bc097243c19dc3381c1ed57' 
  AND token = 'YBhpmQDB5gsg6bdKwH3WAQTvD+ZBroKphWL9wbG79rk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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