SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e7ff2c72d3831e2a75621e301f7e6eb9a4824fcde1f7ec49e113da425d23e8f' 
  AND token = 'CODAVP5zdOSgMgZrBuHG2yNsV+bXoNdO/Fn38jqFK+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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