SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13a1ab9db64fb5a6b5f1de15a470a2cf43798d81f56808078a7fd7469a252d3d' 
  AND token = '7wjj6IP2LTRxnnC/hNNczzAKz5sxyf2c8GGKMJo8tLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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