SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0df0552c99259c585706337ee1da7f9040549a74ce93e2ec704681278dd73bfd' 
  AND token = 'p+r/mmXy3SdN9YBjlnqvPkY/FNKfVh9xkFNGy2PtCoQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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