SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5acc37de9c7a67aacb728abeacf7c0d1429ec0ffe3a732ca1162d9de27ffb985' 
  AND token = 'cC7VapxlfPDhL0RikatYpDproe4QVgJCRgGpZ5wQqcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}