SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7e7c5b955e517a1c1d25193f1d2915b14166742949a80bc08da8dd85f9e266c' 
  AND token = 'OU7uz+l7JTvwUEmqey8ARiau+O5ySGj3hKVyIJDHdp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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