Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1afb6e5112d2debb9f20ff0d83e06cd78c29a087420b0e82fdd9bf3c7ca12a0' 
  AND token = 'GO4gZmbRWsskIDGZQJjE9CbCdFhDcXDRNBPVt+yBejo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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