SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1373593fba784405c41f172c0f6ec99e8353264e27f02ee8b880b308439d77bb' 
  AND token = '29YvtCRuHawDPqokFFCVVis+YrtQ1Kh/HGx+9X/ju/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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