SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80e0eb6887354cb2f9cc292fae3df0a975c15a9a9f89cc74f1afc27c32e3c3c5' 
  AND token = 'qYhHU+dBv37Gsdx/DCVF3+T+ZpLu7lP5MDlkl7xXd+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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