SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4f08a3d1c63de02ea9ac80cd87afd84b537a113d7832f3708b6cfedc515041e' 
  AND token = 'Rw275HnR3A88c3G/v5M/WW54lzh5UXu7p08yJQdUFmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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