SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3baa8f7576f1159d7c3c4d3f49023ee5b77799571cd553d3fad52040486dbb0' 
  AND token = 'yvd3e+XBN+zXVoQ2Lnwl/jiPM9JkoWgsKQqybQ2+7k0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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