SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd826e94b062b84384c769afbaeb01f35be5a8ccfee8d5cba9e328ca91f54bd12' 
  AND token = 'GZv2HixXaCPNldKwaTkfHwQbzgAMVNeeYE/NbLMeV6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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