SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41d92600c6047524879a34c7c59191ea4ccb6c455856771c3d5fc7d655967937' 
  AND token = 'RfZhngmvG/iPPUteHMsNZDprQ2P5IHzLMmOmfS3Y/hM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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