SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea189c20d998f45f7385fa5afe76c14064d3f1f9a451e32fd4a5fb0942bf4c6f' 
  AND token = 'pJrwzNXjQX5LA839SCqxGyXHdJTWoaqGZKmZuOHEOjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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