SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e49b238bcb95c9d7914f994d46fe8212c327f1c096ff0855011885a09b3769e' 
  AND token = 'XCaieGAPo1zua68bd13aT+/PbCllgCZaVrVvEpOzRAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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