SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '864562dbaaeaaadfb58fa7abdfe56c460b2fd5e97c3d98dce7e0bcbf10f595f1' 
  AND token = 'xUZ9FUH26lpncWh2wmLo/ImXg11aEmK+d1cGFUV+INc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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