SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69b255cbffafd764930b3d5283a9518f876f6aa302c2e9b26defde4b8e81e253' 
  AND token = 'cZrEGtAJHoIjeWC09dx7xtoihAIZ6tRPQ0Vv1pS2zsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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