SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '178e417db3090ec9c206bd25abcd2ab197324efb8eabcd5583233a5bbd836b9d' 
  AND token = 'yGTuH7BYnsUTjT7P9KVUrzvOV/Pj7+oM3Fzdt+p5Yqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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