SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a66a2e8646576a96dd9a325d0a42e4b59f413facc1bd3fc440e58c9ff2bf65f' 
  AND token = 'pWG4Nk718mLI47yeji+bPKDz/YfeB+U39XjK/2CELqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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