SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9df914e453d5b3fd3ac4e50dd0964ef4e0fa89f96ffa5438c56aed75cb08d8ef' 
  AND token = '6cRqkwJ/XeVEXYMjojYq4T6vcgATStwlcpIUlOwDYKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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