SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58ca44313519386d8d575e3fa8dc54b4ad2f6023c402bd1e357fd673c956b3f1' 
  AND token = '9U6trZn/ZJrFbquHBzPolX3+dnE5dj2iMYysQRGvGgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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