SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f4ee972d98fbdc8dc469d76cd067fb146200998def67f3c9bb79ab94e62473f' 
  AND token = 'jW2OQPPVMXYR/UrpHmV0NwH2gVzs+UAG0hGFiNlAXvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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