SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7deebbd8f294ce3651dd323894deab3b3044b4b075aa00d74243e9c112644f92' 
  AND token = '7upGbtbumdOzYOnFj4WgsRUTBGNozCNx2wRyWV9ghLY=' 
  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"
    }
  }
}