SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '616a2699934c083b1d05e0bdac6222af0fec48c0447965bb7f50432eefa7ec35' 
  AND token = 'GaZhMakYMFDFjpdCPJetMMakkZkbzjdO/yo4f0wd6tE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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