SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8709e5ee63f7c177faa22bffbdcfa618087c63f9412897392f826fb6bd278b99' 
  AND token = 'JelGbxsFUBSvCn/QFFNNx52XFKmsVbmh0OjDenXjuWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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