SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de404f54803fb175a79616c68d42d8bb8b6d86a39de95de1ad62e21974c860df' 
  AND token = '6wPU/4NH8y3kNB0ZKiROQnpx0UbEvTb4KPic4JYbiu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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