SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '929f4ea77a9b06537793cbb86e5b9f0df544ae62c5d3b3b8b189ac7d63ea6b84' 
  AND token = 'q8KwBA1Jzr/7pPTnOX9CI7UVM8wcbxyitVwPOraYQpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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