SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33bf39229d521baf498b922202a2ae04a2cfc65bbb9f2d070688eca10ea073b7' 
  AND token = 'rHk4QufLDMpW+7QrIpHIZHX7qROHU6FBlGUKtUui4yU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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