SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caab3febbe3b1fe401d69671a70265265140bb1cc9c4633cf127ea5288ae51fc' 
  AND token = 'jQE3ZqQynCz86vkkNyDwco2SFUolhNMByVsEtXCCnrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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