SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c969923024de743647942611131b1366b0b6692f13b25eee58dda359fb5695e' 
  AND token = 'jAn1bFNdteRaFVp4gwgLgHQ7jAXNWfDBNArfsZ14zOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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