SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95c7051b2fda3bf1dd00276d6bbb132110450b16f772578e79a7b66626d0405a' 
  AND token = '7KsAFirfGf+DAql4mIMOKJo/ODvcGbqCZ7t/dzrMBYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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