SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9383318d95ba962a6f66d14fa18d2e3a4985cc6e845b87b3cffd1d1ef7ecabf' 
  AND token = 'TWDMKlOwwQi++eO93uuxYgAY3c9qV84oEf7Db3Y+fXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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